Method for determining feedback information, terminal device, and network device

ABSTRACT

Embodiments of this application provide a method for processing information bits in a wireless communication network. A communication device receives a radio resource control (RRC) signaling, wherein the RRC signaling comprises time window information and time unit format information, wherein the time window information comprises a hybrid automatic repeat request (HARQ) time sequence K1 set, wherein K1 is a time relationship between a time unit of a physical downlink shared channel (PDSCH) and a time unit of a physical uplink control channel (PUCCH), or wherein the K1 is a time relationship between a time unit of a (PDSCH) and a time unit of a physical uplink shared channel (PUSCH). The device determines HARQ feedback information based on the time window information and the time unit format information and sends the HARQ feedback information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.17/127,423, filed on Dec. 18, 2020 (now U.S. Pat. No. 11,601,250), whichis a continuation of U.S. Pat. Application No. 16/787,858, filed on Feb.11, 2020 (now U.S. Pat. No. 10,887,071), which is a continuation ofInternational Application No. PCT/CN2018/100070, filed on Aug. 10, 2018,which claims priority to Chinese Patent Application No. 201710686826.1,filed on Aug. 11, 2017. All of the afore-mentioned patent applicationsare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of wireless communicationstechnologies, and in particular, to a method for determining feedbackinformation, a terminal device, and a network device.

BACKGROUND

To deal with different user requirements, the fifth generation mobilecommunications system (5G) proposes a concept of network slicing. In along term evolution (LTE) system, downlink physical layer data is borneby a physical downlink shared channel (PDSCH). To ensure reliability ofphysical layer data transmission and transmission efficiency, LTE uses ahybrid automatic repeat request (HARQ) mechanism. According to a basicprinciple of the HARQ mechanism, a receive end feeds back, to a transmitend, a decoding result for data received from the transmit end; and whenthe data is correctly decoded, the decoding result that is fed back isan acknowledgement (ACK), or otherwise, the decoding result that is fedback is a negative acknowledgement (NACK). The transmit end mayretransmit the transport block (TB) after receiving the NACK. In theprior art, the receive end may add, to one piece of uplink controlinformation (UCI), decoding results for a plurality of TBs transmittedby the transmit end, and feed back the UCI to the base station. Theplurality of TBs may come from different downlink subframes, differentcode words in multiple-input multiple-output (MIMO), and differentcarriers in carrier aggregation. The decoding result included in the UCIis a HARQ feedback codebook, and a bit quantity of the decoding resultis a size of the HARQ feedback codebook. In the decoding result, acorrespondence between a bit and a TB is an indexing/orchestrationmanner of a codebook.

To better meet ever-increasing requirements of service types, in the newradio access technology (NR), in addition to supporting LTE-supportedenhanced mobile broadband (eMBB) and broadcast services, two new servicetypes: a massive machine-type communications (mMTC) service and anultra-reliable and low-latency communications (URLLC) service are alsointroduced. Because service characteristics, reliability requirements,or latency requirements of different service types vary significantly,requirements on system parameters such as subcarrier spacings and symbolduration of services are different.

In the NR technology, a shorter time unit is used for data transmission.To reduce scheduling control overheads and uplink/downlink transmissionswitching overheads in time division duplex (TDD), multi-time-unitscheduling, or referred to as time unit aggregation, may be introducedto the NR. To be specific, one piece of downlink control information(DCI) can schedule a plurality of time units, and each time unit maycarry one TB or two TBs. Apparently, DCI control overheads can be lowerthan those in a case in which one time unit is scheduled by one piece ofDCI. Because one piece of DCI schedules one time unit in a conventionaldownlink communications system, a scenario in which one piece of DCIschedules a plurality of time units is not considered in the prior-arttechnical solution. After multi-time-unit scheduling or time unitaggregation is introduced, the following problem needs to be urgentlyresolved: How to design HARQ feedback information to ensureunderstanding consistency (including consistency of bit quantities offeedback information and consistency of decoding results for data intime units corresponding to bit quantities) between the transmit end andthe receive end in a scenario of supporting a flexible quantity ofaggregated time units, thereby avoiding occurrence of disorder andensuring communication reliability and robustness.

SUMMARY

This application provides a method for determining feedback information,a terminal device, and a network device, to improve a method fordetermining HARQ feedback information in an NR system, so as to supporta scenario with a flexible quantity of aggregated or scheduled timeunits, thereby avoiding understanding inconsistency and disorder of theHARQ feedback information between a receive device and a transmit deviceon a premise of ensuring downlink control overheads and uplink feedbackoverheads.

According to a first aspect, a method for determining feedbackinformation is provided, including:

obtaining, by a receive end device, control information sent by atransmit end device, where the control information includes time unitaggregation information and downlink assignment index (DAI) indicationinformation, and the DAI indication information includes at least onetype of total downlink assignment index (T-DAI) indication informationand counter downlink assignment index (C-DAI) indication information;determining, by the receive end device, feedback information for atleast one transport block based on the time unit aggregation informationand the DAI indication information; and sending, by the receive enddevice, the feedback information for the at least one transport block tothe transmit end device.

The receive end device obtains the time unit aggregation information andthe DAI indication information that are sent by the transmit end device,determines the feedback information for the at least one transport blockbased on the time unit aggregation information and the DAI indicationinformation, and finally sends the feedback information for the at leastone transport block to the transmit end device. This can improve amanner of determining HARQ feedback information in an NR system, so asto support a scenario with a flexible quantity of aggregated/scheduledtime units, thereby avoiding understanding inconsistency and disorder ofthe feedback information between the receive end device and the transmitend device on a premise of ensuring downlink control overheads anduplink feedback overheads.

In a possible design, the time unit aggregation information includes amaximum quantity of time units that can be scheduled by one piece ofdownlink control information DCI; and the determining, by the receiveend device, feedback information for at least one transport block basedon the time unit aggregation information and the DAI indicationinformation includes: determining, by the receive end device, a bitquantity of the feedback information for the at least one transportblock based on the T-DAI indication information and the maximum quantityof time units that can be scheduled by one piece of DCI; andorchestrating, by the receive end device based on the C-DAI indicationinformation, feedback information for a transport block in a time unitscheduled by the DCI, to a location corresponding to the C-DAIindication information.

Because the bit quantity of the feedback information is obtained basedon the T-DAI indication information and the maximum quantity of timeunits that is configured for a carrier and that can be scheduled by onepiece of DCI, regardless of how many bits scheduled by one piece of DCI,feedback information of the same bit quantity is fed back. Therefore, ina case of DCI loss, disorder of feedback information can be avoided.

In a possible design, the determining, by the receive end device, a bitquantity of the feedback information for the at least one transportblock based on the T-DAI indication information and the maximum quantityof time units that can be scheduled by one piece of DCI includes:determining, by the receive end device, that a product of the T-DAIindication information and the maximum quantity of time units that canbe scheduled by the one piece of DCI is the bit quantity of the feedbackinformation for the at least one transport block.

The receive end device obtains the bit quantity of the feedbackinformation based on the product of the T-DAI indication information andthe maximum quantity of time units that is configured for a carrier andthat can be scheduled by one piece of DCI, so that DCI overheads can bereduced and disorder of feedback information is avoided throughmulti-time-unit scheduling.

In a possible design, the orchestrating, by the receive end device,feedback information for a transport block in a time unit scheduled bythe DCI, to a location corresponding to the C-DAI indication informationincludes: when the maximum quantity of time units that can be scheduledby one piece of DCI is N, and a quantity of time units scheduled by onepiece of DCI is X, where optionally, the quantity X of time unitsscheduled by each piece of DCI is variable, orchestrating, by thereceive end device, the feedback information for the transport block inthe time unit scheduled by the DCI, to first X bits at the locationcorresponding to the C-DAI indication information, and setting (N-X)bits following the first X bits to default values, where X is an integergreater than 1 and less than N.

The foregoing arrangement manner of the feedback information can ensureunderstanding consistency between a transmit end and a receive end inthe scenario of supporting a flexible quantity of aggregated time units,thereby avoiding disorder of the feedback information, and reducing DCIindication overheads.

In a possible design, the orchestrating, by the receive end device,feedback information for a transport block in a time unit scheduled bythe DCI, to a location corresponding to the C-DAI indication informationis specifically: orchestrating, in an order of carriers, feedbackinformation for a transport block in a time unit scheduled by DCI oneach carrier in a first time unit. When a plurality of time units arescheduled by the DCI on a currently orchestrated carrier, feedbackinformation for transport blocks in the plurality of time units is firstorchestrated, and the plurality of time units include a time unitfollowing the first time unit. Then, feedback information for atransport block in a time unit scheduled by the DCI on a subsequentcarrier is orchestrated, the time unit scheduled by the DCI may includethe first time unit, and the first time unit is a currently orchestratedtime unit. After the feedback information for the transport blocks inthe time units scheduled by the DCI on all the carriers in the firsttime unit is orchestrated, feedback information for a transport block ina time unit, scheduled by the DCI on each carrier, following the firsttime unit is orchestrated.

The foregoing arrangement manner of the feedback information can ensureunderstanding consistency between the transmit end and the receive endin the scenario of supporting a flexible quantity of aggregated timeunits, thereby avoiding disorder of the feedback information.

In a possible design, the time unit aggregation information includes aquantity of time units scheduled by the DCI; and the determining, by thereceive end device, feedback information for at least one transportblock based on the time unit aggregation information and the DAIindication information is specifically: when the transmit end deviceconfigures that the receive end device determines the feedbackinformation according to a dynamic codebook mechanism (in animplementation, determining the feedback information based on a DAI), ifa plurality of time units are scheduled by one piece of DCI, performing,by the receive end device, an AND operation on feedback information fortransport blocks in the plurality of time units to generate one-bitfeedback information; orchestrating, by the receive end device, theone-bit feedback information to the location corresponding to a C-DAI inthe DCI; and determining, by the receive end device, the bit quantity ofthe feedback information for the at least one transport block based onthe T-DAI indication information.

The foregoing arrangement manner of the feedback information can ensureunderstanding consistency between the transmit end and the receive endin the scenario of supporting a flexible quantity of aggregated timeunits, thereby avoiding disorder of the feedback information, andreducing DCI indication overheads and UCI feedback overheads.

In a possible design, the time unit aggregation information includes aquantity of time units scheduled by the DCI; and the determining, by thereceive end device, feedback information for at least one transportblock based on the time unit aggregation information and the DAIindication information is specifically: determining, by the receive enddevice, a bit quantity of the feedback information for the at least onetransport block based on the T-DAI indication information; and if aquantity of time units scheduled by one piece of DCI is Y, where Y is aninteger greater than or equal to 1, orchestrating, by the receive enddevice based on the C-DAI indication information, feedback informationfor transport blocks in the Y time units scheduled by the DCI, to Y bitsat the location corresponding to the C-DAI indication information.

The foregoing arrangement manner of the feedback information can ensureunderstanding consistency between the transmit end and the receive endin the scenario of supporting a flexible quantity of aggregated timeunits, thereby avoiding disorder of the feedback information, andreducing UCI feedback overheads.

In a possible design, the time unit aggregation information includeswhether time unit aggregation is configured; and the determining, by thereceive end device, feedback information for at least one transportblock based on the time unit aggregation information and the DAIindication information is specifically: determining, by the receive enddevice based on a T-DAI corresponding to a carrier subset configuredwith time unit aggregation and a maximum quantity of time unitsconfigured for the carrier subset, a bit quantity of feedbackinformation for the carrier subset configured with time unitaggregation; and orchestrating, by the receive end device based on C-DAIindication information in DCI in the carrier subset configured with timeunit aggregation, feedback information for a transport block in a timeunit scheduled by the DCI, to the feedback information for the carriersubset configured with time unit aggregation; and/or determining, by thereceive end device based on a T-DAI corresponding to a carrier subsetconfigured without time unit aggregation, a bit quantity of feedbackinformation for the carrier subset configured without time unitaggregation; orchestrating, by the receive end device based on C-DAIindication information in DCI in the carrier subset configured withouttime unit aggregation, feedback information for a transport block in atime unit scheduled by the DCI, to the feedback information for thecarrier subset configured without time unit aggregation; and combiningthe feedback information for the carrier subset configured with timeunit aggregation and the feedback information for the carrier subsetconfigured without time unit aggregation.

Whether a carrier is configured with time unit aggregation is consideredduring carrier grouping, and therefore feedback information may beseparately determined based on a configuration status of time unitaggregation on each carrier, thereby saving unnecessary DCI indicationoverheads and UCI feedback overheads.

In a possible design, the time unit aggregation information includes aquantity of aggregated time units configured for a carrier; and thedetermining, by the receive end device, feedback information for atleast one transport block based on the time unit aggregation informationand the DAI indication information is specifically: grouping, by thereceive end device, carriers into Z subsets based on the quantity ofaggregated time units configured for a carrier, where quantities ofaggregated time units configured for carriers in one subset are thesame; for the i^(th) subset in the Z subsets, determining, by thereceive end device, a bit quantity of feedback information for thei^(th) subset based on a T-DAI for the i^(th) subset and a quantity oftime units configured for the i^(th) subset; orchestrating, by thereceive end device based on C-DAI indication information in DCI in thei^(th) subset, feedback information for a transport block in a time unitscheduled by the DCI, to the feedback information for the i^(th) subset,where i is greater than or equal to 1 and less than or equal to Z; andcombining Z pieces of feedback information for the Z subsets, where Z isgreater than or equal to 1.

Carriers are grouped into subsets based on information about a quantityof aggregated time units configured on each carrier, and feedbackinformation is separately determined, thereby saving unnecessary DCIindication overheads and UCI feedback overheads.

In a possible design, the time unit aggregation information includeswhether a carrier is configured with or without time unit aggregationand/or includes a quantity of aggregated time units configured for acarrier; and the determining, by the receive end device, feedbackinformation based on the time unit aggregation information, the T-DAIindication information, and the C-DAI indication information isspecifically: separately determining, by the receive end device,feedback information for a carrier that is configured without time unitaggregation or whose configured quantity of aggregated time units is 1and for a carrier that is configured with time unit aggregation and/orwhose quantity of aggregated time units configured for a carrier isgreater than 1.

In a possible design, the receive end device determines, according to adynamic codebook mechanism, feedback information for the carrier that isconfigured without time unit aggregation or whose time unit aggregationis disabled or whose configured quantity of aggregated time units is 1.In an implementation, the receive end device determines, based on theT-DAI indication information and the C-DAI indication information, thefeedback information for the carrier that is configured without timeunit aggregation or whose time unit aggregation is disabled or whoseconfigured quantity of aggregated time units is 1.

In a possible design, the receive end device determines, according to asemi-persistent codebook mechanism, feedback information for the carrierthat is configured with time unit aggregation and/or whose time unitaggregation is enabled and/or whose configured quantity of aggregatedtime units is greater than 1. In an implementation, the receive enddevice determines, based on the time window information, the feedbackinformation for the carrier that is configured with time unitaggregation and/or whose time unit aggregation is enabled and/or whoseconfigured quantity of aggregated time units is greater than 1.

The foregoing embodiment can ensure understanding consistency betweenthe transmit end and the receive end, support a flexible time unitaggregation configuration, and save unnecessary DCI overheads and UCIfeedback overheads.

According to a second aspect, a method for determining feedbackinformation is provided, including:

sending, by a transmit end device, control information to a receive enddevice, where the control information includes time unit aggregationinformation and/or DAI indication information, and the DAI indicationinformation includes at least one type of T-DAI indication informationand C-DAI indication information; and receiving, by the transmit enddevice, feedback information for at least one transport block sent bythe receive end device, where the feedback information is feedbackinformation generated by the receive end device based on the controlinformation.

In a possible design, the time unit aggregation information includes amaximum quantity of time units that can be scheduled by one piece ofdownlink control information DCI.

In a possible design, the time unit aggregation information includes aquantity of time units scheduled by DCI.

In a possible design, the time unit aggregation information includeswhether a carrier is configured with time unit aggregation and/orincludes a quantity of aggregated time units configured for a carrier.

According to a third aspect, a method for determining feedbackinformation is provided, including:

-   obtaining, by a receive end device, control information sent by a    transmit end device, where the control information includes a    monitoring period of a control channel or a control channel resource    and DAI indication information, and the DAI information includes at    least one type of T-DAI indication information and C-DAI indication    information;-   grouping, by the receive end device, carriers into M subsets based    on the monitoring period of a control channel or a control channel    resource, where monitoring periods of control channels or control    channel resources of carriers in one subset are the same; for the    i^(th) subset of the M subsets, determining, by the receive end    device, a bit quantity of feedback information for the i^(th) subset    based on a T-DAI for the i^(th) subset; orchestrating, by the    receive end device based on C-DAI indication information in DCI in    the i^(th) subset, feedback information for a transport block in a    time unit scheduled by the DCI, to feedback information for each    subset, where i is greater than or equal to 1 and less than or equal    to M; and combining M pieces of feedback information for the M    subsets, where M is greater than or equal to 1; and-   sending, by the receive end device, the feedback information to the    transmit end device.

According to a fourth aspect, a method for determining feedbackinformation is provided, including:

-   obtaining, by a receive end device, control information sent by a    transmit end device, where the control information includes T-DAI    indication information and C-DAI indication information, and the    T-DAI indication information and/or the C-DAI indication information    are counted first in ascending order of carrier indexes, then in    ascending order of bandwidth part indexes, and finally in ascending    order of time unit indexes; and determining, by the receive end    device, feedback information based on the T-DAI indication    information and the C-DAI indication information; and-   sending, by the receive end device, the feedback information to the    transmit end device.

In a possible design, the control information includes bandwidth partinformation and time window information, and the bandwidth partinformation is a quantity of bandwidth parts that are configured oractivated or that can be simultaneously activated on a carrier.

In a possible design, the time window information includes a downlinktime unit set that may bear a PDSCH (the feedback information for thePDSCH may be fed back through one piece of target uplink controlinformation), or a set of possible feedback time sequence K1 values.

In a possible design, the determining, by the receive end device,feedback information based on the bandwidth part information and thetime window information includes: determining, by the receive enddevice, a bit quantity of the feedback information based on the quantityof bandwidth parts that are configured or activated or that can besimultaneously activated on a carrier and a time window size.

According to a fifth aspect, a method for determining feedbackinformation is provided, including:

-   obtaining, by a receive end device, control information sent by a    transmit end device, where the control information includes time    window information and time unit format information;-   determining, by the receive end device, feedback information based    on the time window information and the time unit format information;    and-   sending, by the receive end device, the feedback information to the    transmit end device.

In a possible design, the time window information includes a downlinktime unit set that may bear a PDSCH (the feedback information for thePDSCH may be fed back through one piece of target uplink controlinformation) or a set of possible feedback time sequence K1 values, andthe time unit format information includes configured quantity and/orlocation information of time units for bearing uplink transmission in atime window; and the determining, by the receive end device, feedbackinformation based on the time window information and the time unitformat information includes: determining, by the receive end device, abit quantity of the feedback information based on the time window sizeand a quantity of time units for bearing uplink transmission configuredin the time window.

In the process of determining, by the receive end device, the feedbackinformation based on the time window configured by the base station, aDL/UL transmission direction for a time unit also needs to beconsidered, thereby avoiding unnecessary feedback overheads.

According to a sixth aspect, a method for determining feedbackinformation is provided, including:

-   obtaining, by a receive end device, T-DAI indication information and    C-DAI indication information that are sent by a transmit end device,    where statistics of the T-DAI indication information are collected    based on a carrier group, the carrier group includes N subsets, and    statistics of the C-DAI indication information are collected based    on the subsets in the carrier group; and-   determining, by the receive end device, a bit quantity of feedback    information based on the T-DAI indication information; sequentially    cascading feedback information for first (N-1) subsets of the N    subsets; orchestrating the feedback information based on the C-DAI    indication information in order starting from the first bit of the    feedback information, and orchestrating feedback information for the    N^(th) subset based on the C-DAI indication information in reverse    order starting from the last bit of the feedback information.

According to a seventh aspect, a method for determining feedbackinformation is provided, including:

-   obtaining, by a receive end device, control information sent by a    transmit end device, where the control information includes a    configuration parameter of each carrier or bandwidth part and time    window information;-   determining, by the receive end device, a bit quantity of feedback    information based on a configuration parameter relationship of each    carrier or bandwidth part and the time window information; and-   sending, by the receive end device, the feedback information to the    transmit end device.

According to an eighth aspect, a method for determining feedbackinformation is provided, including:

-   obtaining, by a receive end device, first control information and    second control information that are sent by a transmit end device,    where the first control information includes DAI indication    information and indication information of K2, and the second control    information includes time window information or minimum value    information of K1;-   determining, by the receive end device, a bit quantity of feedback    information based on the DAI indication information, the indication    information of K2, and the time window information or the minimum    value information of K1; and-   sending, by the receive end device, the feedback information to the    transmit end device.

In a possible design, the bit quantity of the feedback information isdetermined by DAI+X, where X is a quantity of remaining time unitsfollowing a time unit bearing the first control information in the timewindow.

In a possible design, X=K2-Minimum value of K1.

According to a ninth aspect, a terminal device is provided, including:

-   a transceiver, configured to: obtain control information sent by a    transmit end device, where the control information includes time    unit aggregation information and downlink assignment index DAI    indication information, and the DAI information includes at least    one type of total downlink assignment index T-DAI indication    information and counter downlink assignment index C-DAI indication    information; and send the feedback information to the transmit end    device; and-   a processor, configured to determine feedback information for at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, where-   the transceiver is further configured to send the feedback    information for the at least one transport block to the transmit end    device.

In a possible design, the time unit aggregation information includes amaximum quantity of time units that can be scheduled by one piece ofdownlink control information DCI; and

-   when the processor determines the feedback information for the at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, the processor is specifically configured to:-   determine a bit quantity of the feedback information for the at    least one transport block based on the T-DAI indication information    and the maximum quantity of time units that can be scheduled by one    piece of DCI; and-   orchestrate, based on the C-DAI indication information, feedback    information for a transport block in a time unit scheduled by the    DCI, to a location corresponding to the C-DAI indication    information.

In a possible design, when the processor determines the bit quantity ofthe feedback information for the at least one transport block based onthe T-DAI indication information and the maximum quantity of time unitsthat can be scheduled by one piece of DCI, the processor is specificallyconfigured to:

determine that a product of the T-DAI indication information and themaximum quantity of time units that can be scheduled by one piece of DCIis the bit quantity of the feedback information for the at least onetransport block.

In a possible design, when the processor orchestrates the feedbackinformation for the transport block in the time unit scheduled by theDCI, to the location corresponding to the C-DAI indication information,the processor is specifically configured to:

-   when the maximum quantity of time units that can be scheduled by one    piece of DCI is N, and a quantity of time units scheduled by one    piece of DCI is X, where X is an integer greater than or equal to 1    and less than or equal to N,-   orchestrate the feedback information for the transport block in the    time unit scheduled by the DCI, to first X bits at the location    corresponding to the C-DAI indication information, and set (N-X)    bits following the first X bits to default values.

In a possible design, the time unit aggregation information includes aquantity of time units scheduled by DCI; and

-   when the processor determines the feedback information for the at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, the processor is specifically configured to:-   when a plurality of time units are scheduled by one piece of DCI,    perform, for the receive end device, an AND operation on feedback    information for transport blocks in the plurality of time units to    generate one-bit feedback information, and orchestrate the one-bit    feedback information to a location corresponding to a C-DAI in the    DCI; and-   determine the bit quantity of the feedback information for the at    least one transport block based on the T-DAI indication information.

In a possible design, the time unit aggregation information includes aquantity of time units scheduled by DCI; and

-   when the processor determines the feedback information for the at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, the processor is specifically configured to:-   determine the bit quantity of the feedback information for the at    least one transport block based on the T-DAI indication information;    and-   if a quantity of time units scheduled by one piece of DCI is Y,    orchestrate, based on the C-DAI indication information, feedback    information for transport blocks in the Y time units scheduled by    the DCI, to Y bits at the location corresponding to the C-DAI    indication information, where Y is an integer greater than or equal    to 1.

In a possible design, the time unit aggregation information includes acarrier subset configured with time unit aggregation and/or a carriersubset configured without time unit aggregation; and

-   when the processor determines the feedback information for the at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, the processor is specifically configured to:-   determine, based on a T-DAI corresponding to the carrier subset    configured with time unit aggregation and a maximum quantity of time    units configured for the carrier subset, a bit quantity of feedback    information for the carrier subset configured with time unit    aggregation; and-   orchestrate, based on C-DAI indication information in DCI in the    carrier subset configured with time unit aggregation, feedback    information for a transport block in a time unit scheduled by the    DCI, to the feedback information for the carrier subset configured    with time unit aggregation; and/or-   determine, based on a T-DAI corresponding to the carrier subset    configured without time unit aggregation, a bit quantity of feedback    information for the carrier subset configured without time unit    aggregation; and-   orchestrate, based on C-DAI indication information in DCI in the    carrier subset configured without time unit aggregation, feedback    information for a transport block in a time unit scheduled by the    DCI, to the feedback information for the carrier subset configured    without time unit aggregation; and combine the feedback information    for the carrier subset configured with time unit aggregation and the    feedback information for the carrier subset configured without time    unit aggregation.

In a possible design, the time unit aggregation information includes aquantity of aggregated time units configured for a carrier; and

-   when the processor determines the feedback information for the at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, the processor is specifically configured to:-   group carriers into Z subsets based on the quantity of aggregated    time units configured for a carrier, where configured quantities of    aggregated time units on all carriers in one subset are the same;    and-   for the i^(th) subset of the Z subsets, determine a bit quantity of    feedback information for the i^(th) subset based on a T-DAI for the    i^(th) subset and a quantity of time units configured for the i^(th)    subset; orchestrate, based on C-DAI indication information in DCI in    the i^(th) subset, feedback information for a transport block in a    time unit scheduled by the DCI, to feedback information for each    subset, where i is greater than or equal to 1 and less than or equal    to Z; and combine Z pieces of feedback information for the Z    subsets, where Z is greater than or equal to 1.

In a possible design, the time unit aggregation information includeswhether a carrier is configured with or without time unit aggregationand/or includes a quantity of aggregated time units configured for acarrier; and

-   when the processor determines the feedback information for the at    least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver, the processor is specifically configured to:-   determine, based on the T-DAI indication information and the C-DAI    indication information, feedback information for a carrier that is    configured without time unit aggregation or whose configured    quantity of aggregated time units is 1; and-   determine, based on a time window size, feedback information for a    carrier that is configured with time unit aggregation and/or whose    quantity of aggregated time units configured for a carrier is    greater than 1.

According to a tenth aspect, a network device is provided, including atransceiver and a processor, where

-   the processor is configured to control the transceiver to send    control information to a receive end device, where the control    information includes time unit aggregation information and/or    downlink assignment index DAI indication information, and the DAI    indication information includes at least one type of total downlink    assignment index T-DAI indication information and counter downlink    assignment index C-DAI indication information; and-   the processor is further configured to control the transceiver to    receive feedback information sent by the receive end device for at    least one transport block, where the feedback information is    feedback information generated by the receive end device based on    the control information.

In a possible design, the time unit aggregation information includes amaximum quantity of time units that can be scheduled by one piece ofdownlink control information DCI.

In a possible design, the time unit aggregation information includes aquantity of time units scheduled by DCI.

In a possible design, the time unit aggregation information includeswhether a carrier is configured with or without time unit aggregationand/or includes a quantity of aggregated time units configured for acarrier.

According to an eleventh aspect, a communications system is provided,where the communications system includes the terminal device in theninth aspect and the network device in the tenth aspect.

According to a twelfth aspect, a terminal device is provided, where theterminal device can implement a function of the receive end device inthe foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the first aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of thefirst aspect.

According to a thirteenth aspect, a network device is provided, wherethe network device can implement a function of the receive end device inthe foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the network device includes a processor, a memory,a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the second aspect.

In a possible design, the network device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of thesecond aspect.

According to a fourteenth aspect, a terminal device is provided, wherethe terminal device can implement a function of the receive end devicein the foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the third aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of thethird aspect.

According to a fifteenth aspect, a terminal device is provided, wherethe terminal device can implement a function of the receive end devicein the foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the fourth aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of thefourth aspect.

According to a sixteenth aspect, a terminal device is provided, wherethe terminal device can implement a function of the receive end devicein the foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the fifth aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of thefifth aspect.

According to a seventeenth aspect, a terminal device is provided, wherethe terminal device can implement a function of the receive end devicein the foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the sixth aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of thesixth aspect.

According to an eighteenth aspect, a terminal device is provided, wherethe terminal device can implement a function of the receive end devicein the foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the seventh aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of theseventh aspect.

According to a nineteenth aspect, a terminal device is provided, wherethe terminal device can implement a function of the receive end devicein the foregoing method embodiment, the function may be implemented byhardware or by hardware executing corresponding software, and thehardware or the software includes one or more modules corresponding tothe foregoing function.

In a possible design, the terminal device includes a processor, amemory, a bus, and a communications interface, where the memory stores acomputer-executable instruction; the processor is connected to thememory by using the bus; and when the device runs, the processorexecutes the computer-executable instruction stored in the memory, sothat the device executes the method for determining feedback informationin any possible implementation of the eighth aspect.

In a possible design, the terminal device may be a chip, and the chipincludes a processing unit. Optionally, the chip further includes astorage unit, and the chip may be configured to perform the method fordetermining feedback information in any possible implementation of theeighth aspect.

According to a twentieth aspect, a computer-readable storage medium isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the first aspect.

According to a twenty-first aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the second aspect.

According to a twenty-second aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the third aspect.

According to a twenty-third aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the fourth aspect.

According to a twenty-fourth aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the fifth aspect.

According to a twenty-fifth aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the sixth aspect.

According to a twenty-sixth aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the seventhaspect.

According to a twenty-seventh aspect, a computer-readable storage mediumis provided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the eighth aspect.

According to a twenty-eighth aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the first aspect.

According to a twenty-ninth aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the second aspect.

According to a thirtieth aspect, a computer program product is provided,including a computer-readable instruction, where when a computer readsand executes the computer-readable instruction, the computer performsthe method in any implementation of the third aspect.

According to a thirty-first aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the fourth aspect.

According to a thirty-second aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the fifth aspect.

According to a thirty-third aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the sixth aspect.

According to a thirty-fourth aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the seventhaspect.

According to a thirty-fifth aspect, a computer program product isprovided, including a computer-readable instruction, where when acomputer reads and executes the computer-readable instruction, thecomputer performs the method in any implementation of the eighth aspect.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic structural diagram of a system architectureaccording to this application;

FIG. 2 is a schematic flowchart of a method for determining feedbackinformation according to this application;

FIG. 3 is a schematic diagram of arrangement of time units according tothis application;

FIG. 4 is a schematic diagram of arrangement of time units according tothis application;

FIG. 5 a is a schematic diagram of arrangement of time units accordingto this application;

FIG. 5 b is a schematic diagram of arrangement of time units accordingto this application;

FIG. 5 c is a schematic diagram of arrangement of time units accordingto this application;

FIG. 6 a is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 6 b is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 7 a is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 7 b is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 8 a is a schematic diagram of arrangement of time units accordingto this application;

FIG. 8 b is a schematic diagram of arrangement of time units accordingto this application;

FIG. 9 a is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 9 b is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 10 is a schematic flowchart of determining feedback informationaccording to this application;

FIG. 11 is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 12 is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 13 is a schematic diagram of arrangement of feedback informationaccording to this application;

FIG. 14 is a schematic diagram of arrangement of time units according tothis application;

FIG. 15 is a schematic diagram of arrangement of time units according tothis application;

FIG. 16 is a schematic diagram of arrangement of time units according tothis application;

FIG. 17 is a schematic diagram of arrangement of time units according tothis application;

FIG. 18 is a schematic diagram of arrangement of time units according tothis application;

FIG. 19 is a schematic diagram of arrangement of time units according tothis application;

FIG. 20 is a schematic diagram of arrangement of time units according tothis application;

FIG. 21 is a schematic structural diagram of a terminal device accordingto this application; and

FIG. 22 is a schematic structural diagram of a network device accordingto this application.

DESCRIPTION OF EMBODIMENTS

The following describes the technical solutions of this application withreference to the accompanying drawings in this application. A specificoperation method in method embodiments may also be applied to anapparatus embodiment or a system embodiment. In the descriptions of thisapplication, unless otherwise specified, “plurality” indicates at leasttwo.

Architectures and service scenarios described in this application areintended to more clearly describe the technical solutions in thisapplication, but are not intended to limit the technical solutionsprovided in this application. A person of ordinary skill in the art mayknow that as the network architectures evolve and a new service scenarioemerges, the technical solutions provided in this application arefurther applied to a similar technical problem.

FIG. 1 is a schematic diagram of a possible network architectureapplicable to this application. The network architecture includes atleast one receive end device 10, and the receive end device 10communicates with a transmit end device 20 through a radio interface.For clarity, FIG. 1 shows only one receive end device and one transmitend device. In the network architecture, the receive end device may be aterminal device, and the transmit end device may be a base station. Forease of description, “terminal device” and “base station” are used indescriptions of subsequent operation method procedures.

The terminal device is a device that has a wirelesstransmission/reception function, and the terminal device may be deployedon land, for example, an indoor device, an outdoor device, a handhelddevice, or an in-vehicle device, or may be deployed in the water (forexample, on a ship), or may be deployed in the sky (for example, on aplane, a balloon, or a satellite). The terminal may be a mobile phone, atablet computer (pad), a computer with a wireless transmission/receptionfunction, a virtual reality (VR) terminal, an augmented reality (AR)terminal, a wireless terminal in industrial control, a wireless terminalin self-driving, a wireless terminal in telemedicine (remote medical), awireless terminal in a smart grid, a wireless terminal in transportationsafety, a wireless terminal in a smart city, a wireless terminal in asmart home, or the like.

The base station is a device that connects a terminal to a wirelessnetwork. The base station includes but is not limited to an evolvedNodeB, (eNB), a home evolved NodeB (for example, home evolved nodeB orhome node B, HNB), a baseband unit (BBU), a gNodeB (g nodeB, gNB), atransmission/reception point (TRP), a transmission point (TP), or thelike. In addition, the base station may further include a Wi-Fi accesspoint (AP) or the like.

At present, an LTE system includes two transmission modes: frequencydivision duplex (FDD) and time division duplex (TDD). In an FDD mannerof determining feedback information, in a time unit (an LTE time unit isa subframe) n, the base station sends downlink data to the terminaldevice; and the terminal device feeds back, in a time unit (n+4),whether the feedback information is correctly received. If the dataincludes only one transport block (TB), the terminal device feeds backone-bit feedback information; or if there are two TB blocks (two codewords) in multiple-input multiple-output (MIMO), the terminal devicefeeds back two-bit feedback information.

However, in a TDD manner of determining feedback information, theterminal device detects downlink data transmission in a downlink timeunit (n-k), and the terminal device sends feedback information in anuplink time unit n, where ^(k) ^(∈) ^(K) (whether data in a plurality ofdownlink time units is correctly received needs to be fed back in oneuplink time unit because a quantity of uplink time units is relativelysmall), as shown in Table 1.

TABLE 1 Uplink-downlink configuration Time unit n 0 1 2 3 4 5 6 7 8 90 - - 6 - 4 - - 6 - 4 1 - - 7, 6 4 - - - 7, 6 4 - 2 - - 8, 7, 4,6 - - - - 8, 7, 4, 6 - - 3 - - 7, 6, 11 6, 5 5, 4 - - - - - 4 - - 12, 8,7, 11 6, 5, 4, 7 - - - - - - 5 - - 13, 12, 9, 8, 7, 5, 4, 11,6 - - - - - - - 6 - - 7 7 5 - - 7 7 -

In a case of a TDD configuration of 1, a time unit 7 is an uplink timeunit (n=7), and feedback information of whether downlink data in a timeunit (n-k) (it may be learned that k is 7 or 6 according to Table 1) iscorrectly received, that is, feedback information for downlink data in atime unit 0 and a time unit 1, possibly need to be fed back in the timeunit 7. If data transmitted to the terminal device includes only one TB,two-bit feedback information is fed back in the time unit 7; or if thereare two TB blocks (two code words) in MIMO, four-bit feedbackinformation is fed back.

In conclusion, in TDD system, feedback information for transmission inone or more downlink time units need to be fed back in each uplink timeunit, a downlink time unit set whose reception status needs to be fedback is referred to as a time window (also referred to as a bundlingwindow or an associated set in this application), and a quantity of timeunits included in the set is referred to as a time window size.

In addition, the time window in this application may have the followingtwo interpretations.

1. The time window is a set of downlink time units that possibly bearphysical downlink shared channels (PDSCHs). Hybrid automatic repeatrequest acknowledgements (HARQ-ACKs) for decoding result of the PDSCHsmay be borne in one piece of target uplink UCI. In this case, the timewindow may be determined in relation to K1. For example, for target UCIin a time unit n, a possibly earliest or foremost time unit in a timewindow corresponding to the time unit n is time unit n-“Maximum value ofK1”, and a possibly latest or last time unit in the time windowcorresponding to the time unit n is time unit n-“Minimum value of K1”.For example, for an uplink time unit n, if the minimum value of K1 is 2and the maximum value of K1 is 6, an earliest time unit of a time windowcorresponding to the uplink time unit n is time unit n-6, and a lasttime unit of the time window may be time unit n-2. K1 is a timerelationship between a time unit for transmitting a PDSCH and a timeunit for transmitting a physical uplink control channel (PUCCH) or aphysical uplink shared channel (PUSCH). The PUCCH or PUSCH is used totransmit feedback information or UCI for the data. Specifically, ifdownlink data is sent in the n^(th) time unit on a physical downlinkshared channel (PDSCH), a time unit used to transmit acknowledgementinformation corresponding to the downlink data on a physical uplinkshared channel PUSCH or a physical uplink control channel PUCCH is the(n+K1)^(th) time unit.

2. The time window is a set of downlink time units that possibly bearPDCCHs. HARQ-ACKs for decoding result of PDSCHs scheduled by the PDCCHsmay be borne in one piece of target uplink UCI. In this case, the timewindow may be determined in relation to K1 and K0. For example, fortarget UCI in a time unit n, a possibly earliest or foremost time unitin a time window corresponding to the time unit n is time unitn-“Maximum value of K1”-“Maximum value of K0”, and a possibly latest orlast time unit in the time window corresponding to the time unit n istime unit n-“Minimum value of K”-“Minimum value of K0”. For example, foran uplink time unit n, if the minimum value of K1 is 2, the maximumvalue of K1 is 6, the minimum value of K0 is 0, and the maximum value ofK0 is 4, an earliest time unit of a time window corresponding to theuplink time unit n is time unit n-6-4, and a last time unit of the timewindow may be time unit n-2. K0 may be a time relationship between atime unit for transmitting a PDCCH and a time unit for transmitting aphysical downlink shared channel PDSCH. Specifically, if schedulinginformation is sent on the PDCCH in the n^(th) time unit, a time unitused by the PDSCH scheduled by the PDCCH is the (n+K0)^(th) time unit.

An LTE time window is fixed. In other words, the time window isdetermined based on a TDD uplink-downlink time unit configuration.However, an NR-system time window may be dynamic and configurable.Specifically, K1 and K0 are configured through a combination of radioresource control (RRC) and DCI. In other words, a set of possible valuesof K1 and/or K0 is configured through semi-persistent RRC signaling, andthen specific value information of K1 and/or K0 is notified through DCIsignaling.

During carrier aggregation, a terminal device may determine feedbackinformation based on a configured carrier quantity. For example, theterminal device may determine HARQ feedback information based on a totaldownlink assignment index (T-DAI) and a counter downlink assignmentindex (C-DAI).

The T-DAI may be, in a time window, a total quantity of {carrier, timeunit} pairs scheduled by a PDCCH until a current time unit (and mayfurther include a quantity of PDCCHs used to indicate semi-persistentscheduling release); or a total quantity of PDSCH transmissions until acurrent time unit; or a total quantity of PDCCH-related PDSCHtransmissions (for example, a PDSCH transmission scheduled by a PDCCH)in a current serving cell and/or until a current time unit, and/or, atotal quantity of {carrier, time unit} pairs of PDCCHs used to indicatesemi-persistent scheduling (SPS) release in a current serving celland/or until a current time unit; or a total quantity of PDSCHsscheduled by a base station and having corresponding PDCCHs in a currentserving cell and/or until a current time unit, and/or, a total quantityof PDCCHS used to indicate semi-persistent scheduling (SPS) release in acurrent serving cell and/or until a current time unit; or a totalquantity of PDSCHs scheduled by a base station in a current serving celland/or until a current time unit (where the PDSCH is a PDSCH that has acorresponding PDCCH and/or that has a PDCCH used to indicate SPSrelease); or a total quantity of time units that are scheduled by a basestation in a current serving cell and/or until a current time unit andin which PDSCH transmission is performed (where the PDSCH is a PDSCHthat has a corresponding PDCCH and/or a PDCCH that indicates SPSrelease). It should be noted that a carrier in this application may alsobe referred to as a cell.

The C-DAI is, in a time window, an accumulated quantity of {carrier,time unit} pairs scheduled by a PDCCH until a current time unit (and mayfurther include a quantity of PDCCHs used to indicate SPS release); oran accumulated quantity of PDCCHs until a current time unit; or anaccumulated quantity of PDSCH transmissions until a current time unit;or an accumulated quantity of PDCCH-related PDSCH transmissions (forexample, a PDSCH transmission scheduled by a PDCCH) in a current servingcell and/or until a current time unit, and/or, an accumulated quantityof {carrier, time unit} pairs of PDCCHs used to indicate semi-persistentscheduling (SPS) release; or an accumulated quantity of PDSCHs scheduledby a base station and having corresponding PDCCHs in a current servingcell and/or until a current time unit, and/or, an accumulated quantityof PDCCHs used to indicate SPS release in a current serving cell and/oruntil a current time unit; or an accumulated quantity of PDSCHsscheduled by a base station in a current serving cell and/or until acurrent time unit (where the PDSCH is a PDSCH that has a correspondingPDCCH and/or that has a PDCCH used to indicate SPS release); or anaccumulated quantity of time units that are scheduled by a base stationin a current serving cell and/or until a current time unit and in whichPDSCH transmission is performed (where the PDSCH is a PDSCH that has acorresponding PDCCH and/or a PDCCH that is used to indicate SPSrelease).

As shown in Table 2, a base station configures five carriers, and eachgrid represents one time unit. It is assumed that a HARQ time windowincludes four time units, and a grid filled with D(m,n) represents atime unit in which PDSCH transmission is performed. The PDSCH or thetime unit is scheduled by DCI D(m,n), where m represents a value of atotal-DAI in DCI that schedules the time unit or the PDSCH, and nrepresents a value of a counter-DAI in the DCI that schedules the timeunit or the PDSCH. It is assumed that PDSCHs or data scheduled by DCID(1,1), D(3,2), D(4,4), and D(6,6) are correctly received at a receiveend, that a PDSCH or data scheduled by DCI D(3,3) is incorrectlyreceived at the receive end, and that the receive end does not detectDCI D(6,5). In the 1^(st) time unit in the time window, data isscheduled on only a carrier 1, and therefore T-DAI=1 and C-DAI=1. In the2^(nd) time unit in the time window, data is transmitted on both acarrier 0 and a carrier 2, plus the data transmission in the 1^(st) timeunit, T-DAI=3, the C-DAI is 2 on the carrier 0, and the C-DAI is 3 onthe carrier 2. T-DAIs and C-DAIs in the 3^(rd) time unit and the 4^(th)time unit can be sequentially obtained. Therefore, final HARQ feedbackinformation includes six bits (which is determined by a finally detectedT-DAI in the time window, that is, 6), that is, 110101. For example, 1represents an ACK, and 0 represents a NACK. Because the receive devicedoes not detect the DCI D(6,5), the receive device first maps feedbackinformation for PDSCHs in detected DCI onto locations corresponding tothe C-DAIs (for example, maps data scheduled by the DCI D(1,1) onto the1^(st) bit, that is, an ACK(1)), and a remaining location filled with noinformation (a location corresponding to C-DAI=5, namely, the 5^(th)bit) is filled with NACK. This is an advantage of a DAI mechanism, thatis, a data packet loss can be detected, thereby avoiding understandinginconsistency of feedback information between the base station and theUE. A corresponding PDSCH or TB is counted first in frequency domain andthen in time domain. In other words, the T-DAI and the C-DAI are countedfirst in frequency domain and then in time domain. A HARQ-ACK of a TBcorresponding to DCI whose DAI value is D(1,1) is the 1^(st) bit, aHARQ-ACK of a TB corresponding to DCI whose DAI value is D(3,2) is the2^(nd) bit, and so on. It should be noted that DAI is counted first infrequency domain and then in time domain.

It should be noted that the values 1, 2, 3, 4, 5, and 6 of the T-DAI andthe C-DAI in the example of this application are merely used for ease ofdescription herein. In a protocol, indication information in DCI dependson bit quantities of T-DAI and C-DAI fields in the DCI. For example, inLTE, it is assumed that the T-DAI field and the C-DAI field each includetwo bits, where 1 is represented by 00, 2 is represented by 01, 3 isrepresented by 10, 4 is represented by 11, 5 is represented by 00, 6 isrepresented by 01, and so on. Therefore, when a specific value of theT-DAI is calculated, a quantity of repetition times needs to beconsidered. For example, if the T-DAI field is repeated once and theT-DAI field is 01, it indicates that the value of the T-DAI is 6; or ifthe T-DAI field is repeated twice and the T-DAI field is 10, itindicates that the value of the T-DAI is 11. The same holds true for theC-DAI, and details are not repeated. For details, refer to Table 3.

TABLE 2 CC0 D(3,2) Correct CC1 D(1,1) Correct D(4,4) Correct D(6,5) LostCC2 D(3,3) Incorrect D(6,6) Correct CC3 CC4

TABLE 3 DAI field information C-DAI/T-DAI value corresponding to a DAIfield Actual C-DAI/T-DAI value Y (a quantity of PDCCH-related PDSCHtransmissions (for example, a PDSCH transmission scheduled by a PDCCH),and/or, a quantity of {carrier, time unit} pairs of a PDCCH that is usedto indicate semi-persistent scheduling (SPS) release) 0,0 1 mod(Y -1,4)+1 = 1 0,1 2 mod(Y -1,4)+ 1 = 2 1,0 3 mod(Y -1,4)+ 1 = 3 1,1 4 mod(Y-1,4)+ 1 = 4

To reduce scheduling control overheads and TDD uplink/downlinktransmission switching overheads, use of a shorter time unit isconsidered, and therefore multi-time-unit scheduling, or referred to astime unit aggregation, may be introduced in NR. To be specific, onepiece of DCI may schedule a plurality of time units, and each time unitmay bear one TB or two TBs. Apparently, DCI control overheads can belower than those in a case in which one time unit is scheduled by onepiece of DCI. Because one piece of DCI schedules one time unit in aconventional downlink communications system, a scenario in which onepiece of DCI schedules a plurality of time units is not considered inthe prior-art technical solution. After multi-time-unit scheduling ortime unit aggregation is introduced, the following problem needs to beurgently resolved: How to design HARQ feedback information to ensureunderstanding consistency (including consistency of bit quantities offeedback information and consistency of decoding results for data intime units corresponding to bit quantities) between a transmit end and areceive end in a scenario of supporting a flexible quantity ofaggregated time units, thereby avoiding occurrence of disorder andensuring communication reliability and robustness. For example, it isassumed that the receive device receives two pieces of DCI in a timewindow, that a T-DAI is 3 and a C-DAI is 1 in one piece of DCI, and thata T-DAI is 3 and a C-DAI is 3 in the other piece of DCI. According tothe prior art, the receive device may determine that one piece of DCImay be lost, and that a T-DAI is 3 and a C-DAI is 2 in the lost DCI.However, the receive device does not know a specific carrier thatcorresponds to the lost DCI and a quantity of time units/PDSCHs/TBs thatare scheduled by the lost DCI. Consequently, the receive device does notknow a quantity of bits that actually need to be fed back, and does notknow which corresponding bit information needs to be filled with NACK ordiscontinuous transmission (DTX). This results in understandinginconsistency between the transmit end and the receive end, occurrenceof disorder, and poor robustness of communication.

Based on the foregoing descriptions, the following details the methodfor determining feedback information provided in this application.

Feedback information in this application may be understood as orrepresented as a HARQ-ACK bit sequence

õ₀^(ACK) õ₁^(ACK) , …, õ_(O^(ACK) − 1)^(ACK),

where

O^(ACK)

represents a bit quantity of the feedback information, and

õ_(i)^(ACK)

represents HARQ-ACK bit information at a location of the i^(th) bit.

Embodiment 1

FIG. 2 shows a method for determining feedback information provided inthis application. The method is applicable to the system architectureshown in FIG. 1 , and includes the following steps.

Step 201: A base station sends control information, where the controlinformation includes time unit aggregation information and downlinkassignment index DAI indication information, and the DAI indicationinformation includes at least one type of total downlink assignmentindex T-DAI indication information and counter downlink assignment indexC-DAI indication information.

In this embodiment of this application, the time unit aggregationinformation and the downlink assignment index DAI indication informationthat are included in the control information sent by the base station toa terminal device may be delivered by using one piece of controlinformation. For example, both the time unit aggregation information andthe DAI indication information are delivered by using DCI.Alternatively, the time unit aggregation information and the downlinkassignment index DAI indication information may be separately includedin two pieces of control information. For example, the base stationsends RRC signaling or group common DCI to the terminal device, wherethe RRC signaling or the group common DCI includes the time unitaggregation information; and the base station sends UE-dedicated DCI tothe terminal device, where the UE-dedicated DCI includes the DAIindication information. Specifically, there may be two cases for the DAIindication information. Case 1: The DAI indication information includesonly a DAI field, and this is applicable to a scenario of determiningone piece of carrier feedback information (for example, a scenario ofonly one carrier configured, or a scenario of determining feedbackinformation for each carrier). A physical meaning of the DAI indicationinformation in this case is similar to that of the C-DAI describedabove. Case 2: The DAI indication information includes the T-DAIindication information and C-DAI indication information described above.The second case prevails by default in examples of the embodiments ofthis application, unless otherwise specified, but this is not limited.For the first case, the concept of this application may be directlyused. Time unit aggregation may be understood as that a plurality oftime units are scheduled by one piece of DCI. In an existing LTE system,one piece of DCI schedules only one downlink time unit. With evolutionof communications systems, for various services (for example, short-timeservices) or working at a higher frequency band, a shorter time unitand/or a wider subcarrier spacing are introduced. To reduce overheads(for example, DCI overheads, or TDD uplink/downlink switching guardinterval gap overheads), the base station may configure that one pieceof DCI schedules a plurality of time units. A quantity of time unitsscheduled by the DCI may be referred to as a quantity of aggregated timeunits, and each time unit may bear one TB (configuring one code word,for example, in a scenario of MIMO with 1 to 4 layers) or two TBs(configuring two code words, for example, in a scenario of MIMO with 5to 8 layers), as shown in FIG. 3 . Alternatively, the plurality ofscheduled time units may bear only one TB (configuring one code word,for example, in a scenario of MIMO with 1 to 4 layers) or two TBs(configuring two code words, for example, a scenario of MIMO with 5 to 8layers), as shown in FIG. 4 . This application mainly focuses on thefirst case, that is, each time unit may bear one TB or two TBs.Therefore, if a system supports the two cases, the first case is used bydefault (for example, a signaling configuration is that considered inthe first case), unless otherwise specified.

In this application, a time unit may be a subframe, a transmission timeinterval (one transmission time interval equals a sum of duration ofseveral subframes or a sum of several transmission time intervals equalsduration of one subframe), one time-domain symbol, a plurality oftime-domain symbols, one slot, a plurality of slots, one mini-slot, aplurality of mini-slots, a combination of a mini-slot and a slot, acombination of a symbol and a slot, a combination of a mini-slot and aslot, or the like. Symbol quantities or duration of all time units doesnot need to be the same. If one time unit bears a PDSCH/PDCCH/UCI or thelike, the PDSCH/PDCCH/UCI may not need to fully occupy all time-domainsymbols and/or frequency-domain resources of the time unit. In thisembodiment of this application, for physical meanings of the T-DAIindication information and the C-DAI indication information, refer tothe foregoing descriptions. Details are not described again.

It should be noted that, the description that control information mayinclude T-DAI indication information and C-DAI indication information isused. In a specific application, names may not be limited to “T-DAI” and“C-DAI” provided that a quantity of time units can be indexed. Inaddition, in a specific implementation solution, the T-DAI and the C-DAImay not coexist. Only one DAI may be required, which is referred to as“DAI”. This manner is especially applicable to an application scenarioof determining feedback information for each carrier or an applicationscenario of only one carrier configured. Unless otherwise specified, thedescription “control information includes T-DAI indication informationand C-DAI indication information” is used in this application, which isnot limited thereto. For example, the description “control informationincludes DAI indication information” and the like may also be used.

Step 202: The terminal device obtains the control information sent bythe base station, and determines feedback information for at least onetransport block based on the time unit aggregation information and theDAI indication information.

The feedback information for the at least one transport block is ahybrid automatic repeat request HARQ-ACK, that is, a HARQ-ACK bitsequence

õ₀^(ACK) õ₁^(ACK), …, õ_(O^(ACK) − 1)^(ACK),

for the transport block.

In this embodiment of this application, based on different time unitaggregation information, the following details a procedure ofdetermining the feedback information for the at least one transportblock in a plurality of manners.

Manner 1

In this manner, the time unit aggregation information includes a maximumquantity of time units that can be scheduled by one piece of DCI. A sizeof the feedback information is related to a maximum quantity ofaggregated time units configured by the base station. Therefore, whenobtaining the maximum quantity of time units that can be scheduled byone piece of DCI, the terminal device may determine a bit quantity ofthe feedback information for the at least one transport block based onthe T-DAI indication information and the maximum quantity of time unitsthat can be scheduled by one piece of DCI. Specifically, the terminaldevice may determine the bit quantity of the feedback information forthe at least one transport block based on a product of the T-DAIindication information and the maximum quantity of time units that canbe scheduled by one piece of DCI. Examples are described as follows:

(1) In a case of two TBs or two code words configured on at least onecarrier or in at least one time unit (spatial bundling is disabled ifspatial bundling needs to be considered, for example, in LTE, spatialbundling is set to false or a control message sent by the terminaldevice to the base station does not exceed one threshold (for example, acapacity of the uplink control message)), the final bit quantity

O^(ACK)

of the feedback information is 2*T-DAI*N.

(2) In a case of two TBs or two code words configured on at least onecarrier or in at least one time unit and spatial bundling enabled (forexample, in LTE, spatialBundlingPUCCH is set to true or a controlmessage sent by the terminal device to the base station exceeds onethreshold (for example, a capacity of the uplink control message)), thefinal bit quantity

O^(ACK)

of the feedback information is T-DAI*N.

(3) In a case of one TB or one code word configured on each carrier orin each time unit, the final bit quantity

O^(ACK)

of the feedback information is T-DAI*N.

It should be noted: 1. In the foregoing cases, a code block group (CBG)feedback is not considered, that is, it is assumed that only one bit isfed back for one TB or that one TB includes only one CBG. In a case inwhich a CBG feedback is configured, a feedback bit quantity or a CBGquantity for each TB needs to be additionally considered on the basis ofthis application. 2. If SPS PDSCH transmission is activated and thereceive device needs to receive an SPS PDSCH in a time window, decodingresult information may be further fed back for the SPS PDSCH. 3. Forease of description, it is assumed that one code word or one TB isconfigured, CBG feedback is disabled, no SPS PDSCH transmission isperformed, configuration parameters (numerology) of all carriers are thesame, and duration of time units is the same, unless otherwisespecified. 4. If a restriction on an actual bit quantity of a T-DAIfield is considered, an actual value of a T-DAI is

Lj + V_(T − DAI)^(DL),

where

V_(T − DAI)^(DL)

represents a value of the T-DAI field in DCI, j represents j times ofrepetition of the T-DAI field, and L depends on a bit quantity of theT-DAI field. For example, in LTE, in a case of two bits, thecorresponding L is 4, or in a case of four bits, the corresponding L is16 (counting for L times is a cycle). The same holds true for all theembodiments in this specification, and details are not described again.

In addition, the description “a maximum quantity of time units that canbe scheduled by one piece of DCI” in this application has the followinginterpretations:

(1) After a quantity of aggregated time units is configured throughhigher layer signaling (for example, RRC signaling), a quantity of timeunits scheduled by each piece of DCI is fixedly the quantity ofaggregated time units configured through the higher layer signaling.Therefore, “a maximum quantity of time units that can be scheduled byone piece of DCI” may be understood as “a quantity of time units thatcan be scheduled by one piece of DCI”.

(2) After a quantity of aggregated time units is configured throughhigher layer signaling (for example, RRC signaling), a quantity of timeunits scheduled by each piece of DCI is variable, for example, eachpiece of DCI may indicate value information of the time units scheduledby the DCI, provided that the value is less than or equal to thequantity of aggregated time units configured through the higher layersignaling. Therefore, “a maximum quantity of time units that can bescheduled by one piece of DCI” may be understood as “a maximum quantityof time units that can be scheduled by one piece of DCI”.

(3) In this application, the time unit aggregation information may benot only indicated through explicit signaling, but also obtainedimplicitly. In other words, the quantity of time units may be not onlyindicated through explicit signaling but also implicitly indicated. Forexample, a bitmap in DCI may be used to represent a scheduled time unit(1110 represents that the first three time units are scheduled, so thattime unit quantity information and/or scheduled time unit informationcan be implicitly obtained). For another example, DCI and/or RRC mayconfigure an offset between a start time unit for data transmission anda PDCCH and an offset between an end time unit and the PDCCH (time unitquantity information and/or scheduled time unit information can beimplicitly obtained based on the start and end information).

(4) The maximum quantity of time units that can be scheduled by onepiece of DCI may be configured for each carrier. For example, themaximum quantity of time units that can be scheduled by one piece of DCIconfigured for the i^(th) carrier is Ni; or only a maximum quantity N oftime units that can be scheduled by one piece of DCI is configured andapplied to all carriers. In a case of configuring Ni for each carrier,the maximum quantity N of time units that can be scheduled by one pieceof DCI is a maximum value of Ni in this application. In a case ofconfiguring only the maximum quantity of time units that can bescheduled by one piece of DCI for all the carriers, the maximum quantityof time units that can be scheduled by one piece of DCI is N in thisapplication.

(5) The maximum quantity of time units that can be scheduled by onepiece of DCI may be alternatively system-defined, in other words, themaximum quantity does not need to be notified through signaling, butonly whether to enable time unit aggregation needs to be configuredthrough signaling.

If whether to enable time unit aggregation is configured throughsignaling, the following solution is considered when time unitaggregation is set to be enabled. Other embodiments of this applicationare similar, and details are not described again.

The terminal device orchestrates, based on the C-DAI indicationinformation, HARQ-ACK information for a transport block in a time unitscheduled by DCI, to a location corresponding to the C-DAI indicationinformation. In other words, one piece of DCI includes the C-DAIindication information, and information at a location corresponding tothe C-DAI indication information is HARQ-ACK information for a transportblock in a time unit scheduled by the DCI (the orchestration action isoptional). During orchestration of feedback information, if the maximumquantity of time units that can be scheduled by one piece of DCI is N,and the quantity of time units scheduled by one piece of DCI is X, whereX is an integer greater than or equal to 1 and less than or equal to N,the terminal device may orchestrate the HARQ-ACK information for thetransport block in the time unit scheduled by the DCI to the first Xbits at the location corresponding to the C-DAI indication information,and set (N-X) bits following the X bits to default values. In otherwords, the terminal device orchestrates the HARQ-ACK information for thetransport block in the time unit scheduled by the DCI to the first Xbits of the N-bit feedback information that is fed back, and sets alocation following the X bits to a default value. Alternatively, inother words, the first X bits at the location corresponding to the C-DAIindication information is the HARQ-ACK information for the transportblock in the X time units scheduled by the DCI that includes the C-DAI,and (N-X) bits following the first X bits are default values. TheHARQ-ACK information is a decoding result for data transmitted on thetransport block. For example, correct reception or an ACK is representedby 1, and incorrect reception or a NACK is represented by 0 (this ismerely an example, and is not limited in this specification. Forexample, the ACK may be represented by 0 and the NACK may be representedby 1).

The location corresponding to the C-DAI indication information may bedetermined in the following possible manners.

A case with one code word or one TB configured and CBG feedback disabledis considered. It is assumed that

V_(C − DAI, c, m)

is a value of a C-DAI field in the DCI, and that the DCI is DCI thatschedules a carrier c and that corresponds to data transmission (PDSCH)in the m^(th) time unit in a time window, or DCI that is borne in them^(th) time unit in a time window and that schedules a carrier c, or DCIthat is borne on a carrier c in the m^(th) time unit in a time window.Therefore, the corresponding location determined based on the C-DAIindication information is

N * (Lj + V_(C − DAI, c, m)^(DL) − 1),

where j represents j times of repetition of the C-DAI, and L depends ona bit quantity of the C-DAI field. For example, in LTE, in a case of twobits, the corresponding L is 4, or in a case of four bits, thecorresponding L is 16 (counting for L times is a cycle). N is themaximum quantity, determined in this manner, of time units that can bescheduled by one piece of DCI.

A case with CBG feedback disabled and two TBs or two code wordsconfigured on at least one carrier or in at least one time unit (spatialbundling is disabled if spatial bundling needs to be considered, forexample, in LTE, spatialBundlingPUCCH is set to false or a controlmessage sent by the terminal device to the base station does not exceedone threshold (for example, a capacity of the uplink control message))is considered. It is assumed that

V_(C − DAI, c, m)

is a value of a C-DAI in the DCI, and that the DCI is DCI that schedulesa carrier c and that corresponds to data transmission in the m^(th) timeunit in a time window, or DCI that is borne in the m^(th) time unit in atime window and that schedules a carrier c, or DCI that is borne on acarrier c in the m^(th) time unit in a time window. Therefore, thecorresponding location determined based on the C-DAI indicationinformation is

2N * (Lj + V_(C − DAI, c, m)^(DL) − 1),

where j represents j times of repetition of the C-DAI, and L depends ona bit quantity of the C-DAI field. For example, in LTE, in a case of twobits, the corresponding L is 4, or in a case of four bits, thecorresponding L is 16 (counting for L times is a cycle). N is themaximum quantity, determined in this manner, of time units that can bescheduled by one piece of DCI.

It should be noted that the foregoing formulas merely representcalculation results, and a specific calculation process may not bestrictly performed according to the foregoing formulas. For example, acalculation result may be represented as

N * Lj + N * V_(C − DAI , c, m)^(DL) − N

or another form. This is not limited in this application.

To more clearly describe a location, in feedback information, ofHARQ-ACK information for a transport block in each time unit, thefollowing details manners of orchestrating feedback information.

The terminal device orchestrates, in an order of carriers, HARQ-ACKinformation for a transport block in a time unit scheduled by DCI oneach carrier in a first time unit. When a plurality of time units arescheduled by the DCI on a currently orchestrated carrier, HARQ-ACKinformation for transport blocks in the plurality of time units is firstorchestrated, and the plurality of time units include a time unitfollowing the first time unit. Then, HARQ-ACK information for atransport block in a time unit scheduled by the DCI on a subsequentcarrier is orchestrated, the time unit scheduled by the DCI may includethe first time unit, and the first time unit is a currently orchestratedtime unit. After the HARQ-ACK information for the transport blocks inthe time units scheduled by the DCI on all the carriers in the firsttime unit is orchestrated, HARQ-ACK information for a transport block ina time unit, scheduled by the DCI on each carrier, following the firsttime unit is orchestrated, where previously orchestrated HARQ-ACKinformation is skipped.

For example, FIG. 5 a and FIG. 5 b show two schematic arrangementdiagrams of time units scheduled by DCI. Different time units areconfigured for a CC1, a CC2, a CC3, a CC4, a CC5, and a CC6 shown inFIG. 5 a . A same short time unit is configured for all CCs shown inFIG. 5 b . As shown in FIG. 5 a or FIG. 5 b , it is assumed that themaximum quantity N of time units that can be scheduled by one piece ofDCI is 4. In a time window, the receive device detects that a value ofthe last T-DAI is 6, and therefore determines that the feedback bitquantity is 6*4=24.

In FIG. 5 a or FIG. 5 b , a time unit in the first column is a firsttime unit, that is, a currently orchestrated time unit. Based on theC-DAI indication information, HARQ-ACK information for a transport blockin a current time unit D(4,1) on the CC1 is first orchestrated, and theHARQ-ACK information is located in the 0^(th) bit of feedbackinformation (a location corresponding to a C-DAI is

N * (Lj + V_(C − DAI, c, m)^(DL) − 1)  = 4 * 0 = 0,

where

 V_(C − DAI , c, m) = 1,  L = 4,  andj = 0

). Because the DCI schedules only one time unit, the first bit of N bitsstarting from the 0^(th) bit corresponds to the feedback information forthe TB in the time unit scheduled by the DCI, and the remaining threebits may be filled with default values (for example, ACK, NACK, DTX, 1,or 0). Then, HARQ-ACK information for a transport block in a currenttime unit D(4,2) on the CC3 is orchestrated, and the HARQ-ACKinformation is located in the 4^(th) bit of the feedback information (alocation corresponding to a C-DAI is

N * (Lj + V_(C − DAI, c, m)^(DL) − 1) = 4 * 1 = 4,

where

V_(C − DAI , c, m) = 2,  L = 4,  andj = 0

). Because the DCI schedules only one time unit, the first bit of N bitsstarting from the 4^(th) bit corresponds to the feedback information forthe TB in the time unit scheduled by the DCI, and the remaining threebits may be filled with default values (for example, ACK, NACK, DTX, 1,or 0). When the CC5 is orchestrated, DCI on the CC5 schedules four timeunits. After HARQ-ACK information for a transport block in a currenttime unit scheduled by the DCI is orchestrated, HARQ-ACK information fortransport blocks in three time units following the current time unit onthe CC5 is continuously orchestrated, and then HARQ-ACK information fora transport block in a time unit in the first piece of DCI on the CC6 isorchestrated. Specifically, HARQ-ACK information for a transport blockin a current time unit D(4,3) on the CC5 is orchestrated, and theHARQ-ACK information is located in the 8^(th) bit of the feedbackinformation (a location corresponding to a C-DAI is

N * (Lj + V_(C − DAI, c, m)^(DL) − 1) = 4 * 2 = 8,

where

V_(C − DAI, c, m) = 3,  L = 4andj = 0

). Because the DCI schedules four time units, N bits starting from the8^(th) bit are feedback information for data in the four time unitsscheduled by the DCI. On the CC4, a time unit in the first column is notscheduled, but a time unit in the second column is scheduled. Therefore,the terminal device needs to skip the CC4, and first orchestratesHARQ-ACK information for a transport block in a time unit in the firstpiece of DCI on the CC6. After orchestrating the time unit in the firstpiece of DCI on the CC6, the terminal device orchestrates HARQ-ACKinformation for a transport block in a time unit scheduled by DCI on theCC4. Finally, the terminal device orchestrates HARQ-ACK information fora transport block in a time unit in the second piece of DCI on the CC6.Specific location information is shown in FIG. 6 a .

In this application, feedback information for data in a later time unitmay be arranged before feedback information for data in an early timeunit. For example, feedback information in the 2^(nd) time unit on theCC5 is arranged before feedback information in the 1^(st) time unit onthe CC6 for ease of organization and management, thereby avoidingunderstanding inconsistency between a transmit device and a receivedevice. It should be noted: 1. In a case of DCI loss, a locationcorresponding to a C-DAI of the DCI is filled with no information(because the DCI and the C-DAI are lost). The location filled with nofeedback information may be filled with NACK or DTX (data packet or DCIloss is mainly considered herein). 2. In a case with two TBs or two codewords configured, a 2N-bit feedback message needs to be arranged at alocation corresponding to a C-DAI. First N bits may be organized tocorrespond to the first TB or N bits of the first code word (if only Xtime units are scheduled, the first X bits are corresponding feedbackinformation, and the following (N-X) bits are default values); and thefollowing N bits are organized to correspond to the second TB or N bitsof the second code word (if only X time units are scheduled, the first Xbits are corresponding feedback information, and the following (N-X)bits are default values). Alternatively, the 2N bits of the feedbackinformation may be alternately arranged. For example, N bits atodd-numbered locations correspond to the first TB or N bits of the firstcode word, and N bits at even-numbered locations correspond to thesecond TB or N bits of the second code word; or N bits at even-numberedlocations correspond to the first TB or N bits of the first code word,and N bits at odd-numbered locations correspond to the second TB or Nbits of the second code word. 3. In the foregoing examples, the values 5and 6 for the T-DAI and the C-DAI may be used for ease of description.In a protocol, indication information in DCI depends on bit quantitiesof T-DAI and the C-DAI fields in the DCI. For example, in LTE, it isassumed that both the T-DAI field and the C-TDAI field include two bits,and therefore 5 should be corrected to 1, representing the C-DAI fieldis repeated once (

j = 1  andV_(C − DAI, c, m) = 1

); and 6 may be corrected to 2, representing the C-DAI field is repeatedtwice (

j = 1  andV_(C − DAI , c, m) = 2

). 4. In the foregoing examples, a start bit is set to the 0^(th) bit,but this is not limited during implementation. For example, the startbit may be set to the 1^(st) bit (if so, the corresponding formula orcalculation result needs to be adjusted, and details are not described).

For example, as shown in FIG. 5 a or FIG. 5 b , after DCI D(4,2) is lost(the receive device does not detect the DCI), HARQ-ACK information for atransport block in a current time unit D(4,1) on the CC1 is firstorchestrated based on the C-DAI indication information, and the HARQ-ACKinformation is located in the 0^(th) bit of the feedback information (alocation corresponding to a C-DAI is

N * (Lj + V_(C − DAI, c, m)^(DL) − 1)  = 4 * 0 = 0,

where

 V_(C − DAI , c, m) = 1,  L = 4,  andj = 0

). Because the DCI schedules only one time unit, the first bit of N bitsstarting from the 0^(th) bit corresponds to feedback information for theTB in the time unit scheduled by the DCI, and the remaining three bitsmay be filled with default values (for example, ACK, NACK, DTX, 1, or0). When the CC5 is orchestrated, DCI on the CC5 schedules four timeunits. After HARQ-ACK information for a transport block in a currenttime unit scheduled by the DCI is orchestrated, HARQ-ACK information fortransport blocks in three time units following the current time unit onthe CC5 is continuously orchestrated, and then HARQ-ACK information fora transport block in a time unit in the first piece of DCI on the CC6 isorchestrated. Specifically, HARQ-ACK information for a transport blockin a current time unit D(4,3) on the CC5 is orchestrated, and theHARQ-ACK information is located in the 8^(th) bit of the feedbackinformation (a location corresponding to a C-DAI is,

N * (Lj + V_(C − DAI, c, m)^(DL) − 1) = 4 * 2 = 8,

where

V_(C − DAI , c, m) = 3,  L = 4, andj = 0

). Because the DCI schedules four time units, N bits starting from the8^(th) bit are feedback information for data in the four time unitsscheduled by the DCI. On the CC4, a time unit in the first column is notscheduled, but a time unit in the second column is scheduled. Therefore,the terminal device needs to skip the CC4, and first orchestratesHARQ-ACK information for a transport block in a time unit in the firstpiece of DCI on the CC6. After orchestrating the time unit in the firstpiece of DCI on the CC6, the terminal device orchestrates HARQ-ACKinformation for a transport block in a time unit scheduled by DCI on theCC4. Finally, the terminal device orchestrates HARQ-ACK information fora transport block in a time unit in the second piece of DCI on the CC6.Then, in 24 bits, locations filled with no HARQ-ACK bits are filled withNACK. To be specific, locations (four bits starting with the 4^(th) bit)corresponding to a C-DAI in the DCI D(4,2) are filled with NACK becausethe DCI is not detected. Therefore, a location corresponding to a C-DAI(the location corresponding to the C-DAI is

N * (Lj + V_(C − DAI, c, m)^(DL) − 1) = 4 * 1 = 4,

where

V_(C − DAI , c, m) = 2,  L = 4, andj = 0

) is filled with no HARQ-ACK bit. Specific location information is shownin FIG. 6 b .

Beneficial effects of this application are that indication overheads ofa C-DAI and a T-DAI in DCI are reduced in a scenario of supporting aflexible quantity of aggregated/scheduled time units. In the foregoingexamples, the C-DAI/T-DAI field requires only two bits; otherwise, thebit quantity of the C-DAI/T-DAI field should be at least greater thanlog₂(N), as described in Manner 3. In addition, in this manner, for acarrier that is configured without time aggregation or DCI thatschedules only one time unit, feedback information also needs to bedetermined based on N. Therefore, in a case of DCI loss, this can avoidunderstanding inconsistency between a receive device and a transmitdevice (it is determined that N bits need to be fed back regardless ofthe DCI lost on any carrier).

Manner 2

In this manner, the time unit aggregation information may include aquantity of time units scheduled by DCI or a time unit scheduled by DCI.

A size of feedback information is unrelated to a quantity of aggregatedtime units. Similar to the case of one code word configured in an LTEsystem, a bit quantity

O^(ACK)

of the feedback information is a value of a T-DAI.

When a base station configures a dynamic codebook (or referred to asdetermining HARQ-ACK information in a dynamic manner; and in a manner,for example, determines HARQ-ACK information based on a DAI) for aterminal device, optionally, when at least two carriers are configured,if one piece of DCI schedules a plurality of time units, the terminaldevice performs an AND operation on HARQ-ACK information for transportblocks in the plurality of time units, to generate one-bit HARQ-ACKinformation; and then orchestrates the one-bit HARQ-ACK information to alocation corresponding to a C-DAI in the DCI. In other words,information at the location corresponding to the C-DAI in the DCI is theone-bit HARQ-ACK information (the orchestration action is optional). Theterminal device determines a bit quantity of the feedback informationbased on T-DAI indication information.

A process of determining the location corresponding to the C-DAIindication information may be as follows.

A case with one code word or one TB configured and CBG feedback disabledis considered. It is assumed that

V_(C − DAI, c, m)

is a value of a C-DAI in the DCI, and that the DCI is DCI that schedulesa carrier c and that corresponds to data transmission in the m^(th) timeunit in a time window, or DCI that is borne in the m^(th) time unit in atime window and that schedules a carrier c, or DCI that is borne on acarrier c in the m^(th) time unit in a time window. Therefore, thecorresponding location determined based on the C-DAI indicationinformation is

Lj + V_(C − DAI, c, m)^(DL) − 1,

where j represents j times of repetition of the C-DAI, and L depends ona bit quantity of the C-DAI field. For example, in LTE, in a case of twobits, the corresponding L is 4, or in a case of four bits, thecorresponding L is 16 (counting for L times is a cycle).

A case with CBG feedback disabled and two TBs or two code wordsconfigured on at least one carrier or in at least one time unit (spatialbundling is disabled if spatial bundling needs to be considered, forexample, in LTE, spatialBundlingPUCCH is set to false or a controlmessage sent by the terminal device to the base station does not exceedone threshold (for example, a capacity of the uplink control message))is considered. It is assumed that

V_(C − DAI, c, m)

is a value of a C-DAI in the DCI, and that the DCI is DCI that schedulesa carrier c and that corresponds to data transmission in the m^(th) timeunit in a time window, or DCI that is borne in the m^(th) time unit in atime window and that schedules a carrier c, or DCI that is borne on acarrier c in the m^(th) time unit in a time window. Therefore, thecorresponding location determined based on the C-DAI indicationinformation is

Lj + V_(C − DAI, c, m)^(DL) − 1,

where j represents j times of repetition of the C-DAI, and L depends ona bit quantity of the C-DAI field. For example, in LTE, in a case of twobits, the corresponding L is 4, or in a case of four bits, thecorresponding L is 16 (counting for L times is a cycle).

It should be noted that the foregoing formulas merely representcalculation results, and a specific calculation process may not bestrictly performed according to the foregoing formulas. This is notlimited in this application.

In Manner 2, the manner of determining the bit quantity of the feedbackinformation is similar to that in the LTE system. To be specific, in acase with one code word configured, the bit quantity of the feedbackinformation is a value of a T-DAI, in other words, only one bit is fedback for a plurality of time units scheduled by each piece of DCI. Adifference lies in that the one bit is a result of an “AND” operationperformed on HARQ-ACK information for transport blocks in the pluralityof time units scheduled by the DCI. For example, one piece of DCIschedules three time units, and when decoding results for transportblocks in the three time units are an ACK(1), an ACK(1), and an ACK(1),after an “AND” operation is performed on the decoding results, adecoding result is still an ACK(1). However, when time units fortransport blocks in the three time units are an ACK(0), an ACK(1), andan ACK(1), after an “AND” operation is performed on the decodingresults, a decoding result is a NACK(0).

For example, as shown in FIG. 5 a or FIG. 5 b , in the time window, thereceive device detects that a value of the last T-DAI is 6, andtherefore the receive device determines that the feedback bit quantity

O^(ACK)

is 6.

In FIG. 5 a or FIG. 5 b , a time unit in the first column is a firsttime unit, that is, a currently orchestrated time unit. HARQ-ACKinformation for a transport block in a current time unit D(4,1) on theCC1 is first orchestrated based on the C-DAI indication information, andthe HARQ-ACK information is located in the 0^(th) bit of feedbackinformation (a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − 1 = 0,

where

V_(C − DAI, c, m) = 1,  L = 4,  andj = 0

). Because the DCI schedules only one time unit, the 0^(th) bitcorresponds to the feedback information for the TB in the time unitscheduled by the DCI. Then, HARQ-ACK information for a transport blockin a current time unit D(4,2) on the CC3 is orchestrated, and theHARQ-ACK information is located in the 1^(st) bit of the feedbackinformation (a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − 1 = 0,

where

V_(C − DAI, c, m) = 2,  L = 4,  andj = 0

). Because the DCI schedules only one time unit, the 1^(st) bitcorresponds to the feedback information for the TB in the time unitscheduled by the DCI. When the CC5 is orchestrated, DCI on the CC5schedules four time units. Specifically, the HARQ-ACK information forthe transport block in a current time unit D(4,3) on the CC5 isorchestrated, and the HARQ-ACK information is located in the 2^(nd) bitof the feedback information (a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − 1 = 0,

where

 V_(C − DAI, c, m) = 3,  L = 4,  and j = 0

). Because the DCI schedules four time units, the 3^(rd) bit is a resultof an “AND” operation performed on feedback information for data in thefour time units scheduled by the DCI. On the CC4, a time unit in thefirst column is not scheduled, but a time unit in the second column isscheduled. Therefore, the terminal device needs to skip the CC4, andfirst orchestrates HARQ-ACK information for a transport block in a timeunit in the first piece of DCI on the CC6. After orchestrating the timeunit in the first piece of DCI on the CC6, the terminal deviceorchestrates HARQ-ACK information for a transport block in a time unitscheduled by DCI on the CC4. Finally, the terminal device orchestratesHARQ-ACK information for a transport block in a time unit in the secondpiece of DCI on the CC6. Specific location information is shown in FIG.7 a .

In a case of DCI loss, a location corresponding to a C-DAI in the DCI isfilled with no information (because the DCI and the C-DAI are lost), andthe location filled with no feedback information may be filled with NACKor DTX.

For example, as shown in FIG. 5 a or FIG. 5 b , after the DCI D(4,2) islost, HARQ-ACK information for a transport block in a current time unitD(4,1) on the CC1 is first orchestrated based on the C-DAI indicationinformation, and the HARQ-ACK information is located in the 0^(th) bitof the feedback information (a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − 1 = 0,

where

V_(C − DAI, c, m) = 1,   L = 4,  andj = 0

). Because the DCI schedules only one time unit, the 0^(th) bitcorresponds to feedback information for the TB in the time unitscheduled by the DCI. When the CC5 is orchestrated, DCI on the CC5schedules four time units. Specifically, HARQ-ACK information for atransport block in a current time unit D(4,3) on the CC5 isorchestrated, and the HARQ-ACK information is located in the 2^(nd) bitof the DL feedback information (a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − 1 = 0,

where

V_(C − DAI, c, m) = 3, L = 4,  andj = 0

). Because the DCI schedules four time units, the 3^(rd) bit is a resultof an “AND” operation performed on feedback information for data in thefour time units scheduled by the DCI. On the CC4, a time unit in thefirst column is not scheduled, but a time unit in the second column isscheduled. Therefore, the terminal device needs to skip the CC4, andfirst orchestrates HARQ-ACK information for a transport block in a timeunit in the first piece of DCI on the CC6. After orchestrating the timeunit in the first piece of DCI on the CC6, the terminal deviceorchestrates HARQ-ACK information for a transport block in a time unitscheduled by DCI on the CC4. Finally, the terminal device orchestratesHARQ-ACK information for a transport block in a time unit in the secondpiece of DCI on the CC6. Then, in six bits, a location filled with noHARQ-ACK bit is set to NACK. To be specific, a location (the 1^(st) bit)corresponding to a C-DAI in the DCI D(4,2) is a NACK because the DCI isnot detected. Therefore, a location corresponding to a C-DAI (thelocation corresponding to the C-DAI is

Lj + V_(C − DAI , c, m)^(DL) − 1  = 2,

where

V_(C − DAI , c, m)  = 2,  L = 4,  andj = 0

) is filled with no HARQ-ACK bit. Specific location information is shownin FIG. 7 b .

In this manner, it may be understood that an “AND” operation is adefault operation that is performed in a configuration in which feedbackinformation is determined according to a dynamic codebook (for example,according to a DAI mechanism) and optionally, in a configuration of atleast two carriers. This means that, for example, the “AND” operation isperformed without requiring an additional signaling notification. To bespecific, when the dynamic codebook is configured (for example,according to the DAI mechanism) to determine feedback information, andoptionally, at least two carriers are configured, if one piece of DCIschedules a plurality of time units, the transmit end and the receiveend both know to perform the “AND” operation to determine feedbackinformation. Certainly, signaling may be additionally introduced tonotify whether to enable the “AND” operation.

In this manner, similar to Manner 1, indication overheads of a C-DAI anda T-DAI in DCI can be reduced in a scenario of supporting a flexiblequantity of aggregated/scheduled time units. In the foregoing examples,the C-DAI/T-DAI field requires only two bits; otherwise, the bitquantity of the C-DAI/T-DAI field should be at least greater thanlog₂(N), as described in Manner 3. In addition, feedback overheads canbe further reduced, for example, feedback overheads can be reduced bythree times. In a case of DCI loss, this manner can also avoidunderstanding inconsistency between a receive device and a transmitdevice (it is determined that one bit needs to be fed back regardless ofthe DCI lost on any carrier).

Manner 3

In this manner, the time unit aggregation information includes aquantity of time units scheduled by DCI or a time unit scheduled by DCI.The terminal device determines a bit quantity of feedback informationbased on T-DAI indication information. Different from Manner 1 in whichN bits are fixedly fed back, in Manner 3, a quantity of time unitsscheduled by one piece of DCI is equal to the feedback bit quantity offeedback information.

If the quantity of time units scheduled by one piece of DCI is Y, whereY is an integer greater than or equal to 1; and the receive end deviceorchestrates, based on the C-DAI indication information, HARQ-ACKinformation for transport blocks in the Y time units scheduled by theDCI, to Y bits at a location corresponding to the C-DAI indicationinformation. In other words, the Y bits at the location corresponding tothe C-DAI indication information are the HARQ-ACK information for thetransport blocks in the Y time units scheduled by the DCI.

A process of determining the location corresponding to the C-DAIindication information may be as follows.

A case with one code word or one TB configured and CBG feedback disabledis considered. It is assumed that

V_(C − DAI , c, m)

is a value of a C-DAI in the DCI, and that the DCI is DCI that schedulesa carrier c and that corresponds to data transmission in the m^(th) timeunit in a time window, or DCI that is borne in the m^(th) time unit in atime window and that schedules a carrier c, or DCI that is borne on acarrier c in the m^(th) time unit in a time window. Therefore, thecorresponding location determined based on the C-DAI indicationinformation is

Lj + V_(C − DAI , c, m)^(DL) − N_( c, m )

or

Lj + V_(C − DAI , c, m)^(DL)

(which depends on whether a quantity

N_( c, m)

of time units scheduled by current DCI is included during DAI statisticscollection, and if included, the location is a result of the formerformula; otherwise, the location is a result of the latter formula),where

N_( c, m)

represents the quantity of time units scheduled by the DCI, j representsj times of repetition of the C-DAI, and L depends on a bit quantity ofthe C-DAI field. For example, in LTE, in a case of two bits, thecorresponding L is 4, or in a case of four bits, the corresponding L is16 (counting for L times is a cycle).

A case with CBG feedback disabled and two TBs or two code wordsconfigured on at least one carrier or in at least one time unit (spatialbundling is disabled if spatial bundling needs to be considered, forexample, in LTE, spatialBundlingPUCCH is set to false or a controlmessage sent by the terminal device to the base station does not exceedone threshold (for example, a capacity of the uplink control message))is considered. It is assumed that

V_(C − DAI , c, m)

is a value of a C-DAI in the DCI, and that the DCI is DCI that schedulesa carrier c and that corresponds to data transmission in the m^(th) timeunit in a time window, or DCI that is borne in the m^(th) time unit in atime window and that schedules a carrier c, or DCI that is borne on acarrier c in the m^(th) time unit in a time window. Therefore, thecorresponding location determined based on the C-DAI indicationinformation is

2 * (Lj + V_(C − DAI , c, m)^(DL) − N _(c, m))

or

2 * (Lj + V_(C − DAI, c, m)^(DL))

(which depends on whether a quantity of currently scheduled time unitsis included during DAI statistics collection, and if included, thelocation is a result of the former formula; otherwise, the location is aresult of the latter formula), where

N_( c, m)

represents the quantity of time units scheduled by the DCI, j representsj times of repetition of the C-DAI, and L depends on a bit quantity ofthe C-DAI field. For example, in LTE, in a case of two bits, thecorresponding L is 4, or in a case of four bits, the corresponding L is16 (counting for L times is a cycle). In this application, a same bitquantity of the T-DAI field and a same bit quantity of the C-TDAI fieldmay be configured for DCI that schedules all carriers, provided that thequantities are greater than log₂(the maximum quantity of time units).This can unify and simplify a design. Alternatively, the T-DAI field andthe C-TDAI field in the DCI on each carrier may be related to the timeunit aggregation information on the carrier, provided that both thevalues of the T-DAI field and the C-TDAI field are greater thanlog₂(Ni). In this way, DCI overheads can be reduced.

It should be noted that the foregoing formulas merely representcalculation results, and a specific calculation process may not bestrictly performed according to the foregoing formulas. This is notlimited in this application. During DAI statistics collection, aquantity of actually scheduled time units needs to be considered, andindicating a quantity of pieces of DCI or a quantity of PDCCHs (theC-DAI in the DCI increases by 1 each time) is not enough.

To more clearly describe a location, in feedback information, ofHARQ-ACK information for a transport block in each time unit, thefollowing details manners of orchestrating feedback information.

The terminal device orchestrates, in an order of carriers, HARQ-ACKinformation for a transport block in a time unit scheduled by DCI oneach carrier in a first time unit. When a plurality of time units arescheduled by the DCI on a currently orchestrated carrier, HARQ-ACKinformation for transport blocks in the plurality of time units is firstorchestrated, and the plurality of time units include a time unitfollowing the first time unit. Then, HARQ-ACK information for atransport block in a time unit scheduled by the DCI on a subsequentcarrier is orchestrated, the time unit scheduled by the DCI may includethe first time unit, and the first time unit is a currently orchestratedtime unit. After the HARQ-ACK information for the transport blocks inthe time units scheduled by the DCI on all the carriers in the firsttime unit is orchestrated, HARQ-ACK information for a transport block ina time unit, scheduled by the DCI on each carrier, following the firsttime unit is orchestrated, where previously orchestrated HARQ-ACKinformation is skipped.

For example, FIG. 8 a and FIG. 8 b show two schematic arrangementdiagrams of time units scheduled by DCI on carriers. As shown in FIG. 8a , different time units are configured for a CC1, a CC2, a CC3, a CC4,a CC5, and a CC6. A same time unit is configured for all CCs shown inFIG. 8 b . As shown in FIG. 8 a or FIG. 8 b , the receive device detectsthat a value of the last T-DAI is 11 in a time window, and therefore thereceive device determines that the feedback bit quantity is 11.

In FIG. 8 a or FIG. 8 b , a time unit in the first column is a firsttime unit, that is, a currently orchestrated time unit. Based on theC-DAI indication information, HARQ-ACK information for a transport blockin a current time unit D(8,1) on the CC1 is first orchestrated, and theHARQ-ACK information is located in the 0^(th) bit of feedbackinformation (it is assumed that a quantity of time units scheduled bycurrent DCI is included during DAI statistics collection, and a locationcorresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − N_(c, m)  = 0,

where

V_(C − DAI , c, m) = 1,

 N_(c, m)  = 1, L = 16,  andj = 0

). Because the DCI schedules only one time unit, the first bit startingfrom the 0^(th) bit corresponds to the feedback information for the TBin the time unit scheduled by the DCI. Then, HARQ-ACK information for atransport block in a current time unit D(8,2) on the CC3 isorchestrated, and the HARQ-ACK information is located in the 1^(st) bitof the feedback information (a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − N _(c, m)  = 1,

where

V_(C − DAI, c, m)  = 2,

N_( c, m)  = 1, L=16, and j=0

). Because the DCI schedules only one time unit, the first bit startingfrom the 1^(st) bit corresponds to the feedback information for the TBin the time unit scheduled by the DCI. When the CC5 is orchestrated, DCIon the CC5 schedules four time units. After HARQ-ACK information for atransport block in a current time unit is orchestrated, HARQ-ACKinformation for transport blocks in three time units following thecurrent time unit on the CC5 is continuously orchestrated, and thenHARQ-ACK information for a transport block in a time unit in the firstpiece of DCI on the CC6 is orchestrated. Specifically, HARQ-ACKinformation for a transport block in a current time unit D(8,6) on theCC5 is orchestrated, and the HARQ-ACK information is located in the2^(nd) bit of the feedback information (a location corresponding to aC-DAI is

Lj + V_(C − DAI, c, m)^(DL) − N _(c, m)  = 2,

where

V_(C − DAI, c, m)  = 6,

N_( c, m)  = 4, L=16, and j=0

). Because the DCI schedules four time units, four bits starting fromthe 2^(nd) bit are feedback information for data in the four time unitsscheduled by the DCI. On the CC4, a time unit in the first column is notscheduled, but a time unit in the second column is scheduled. Therefore,the terminal device needs to skip the CC4, and first orchestratesHARQ-ACK information for a transport block in a time unit in the firstpiece of DCI on the CC6. After orchestrating the time unit in the firstpiece of DCI on the CC6, the terminal device orchestrates HARQ-ACKinformation for a transport block in a time unit scheduled by DCI on theCC4. Finally, the terminal device orchestrates HARQ-ACK information fora transport block in a time unit in the second piece of DCI on the CC6.Specific location information is shown in FIG. 9 a .

In a case of DCI loss, a location corresponding to a C-DAI in the DCI isfilled with no information (because the DCI and the C-DAI are lost), andthe location filled with no feedback information may be filled with NACKor DTX.

For example, as shown in FIG. 8 a or FIG. 8 b , after DCI D(8,2) islost, based on the C-DAI indication information, HARQ-ACK informationfor a transport block in a current time unit D(8,1) on the CC1 is firstorchestrated, and the HARQ-ACK information is located in the 0^(th) bitof feedback information (it is assumed that a quantity of time unitsscheduled by current DCI is included during DAI statistics collection,and a location corresponding to a C-DAI is

Lj + V_(C − DAI, c, m)^(DL) − N _(c, m)  = 0,

where

V_(C − DAI, c, m)  = 1,

N_( c, m)  = 1, L=16, and j=0

). Because the DCI schedules only one time unit, the first bit startingfrom the 0^(th) bit corresponds to the feedback information for the TBin the time unit scheduled by the DCI. When the CC5 is orchestrated, DCIon the CC5 schedules four time units. After HARQ-ACK information for atransport block in a current time unit is orchestrated, HARQ-ACKinformation for transport blocks in three time units following thecurrent time unit on the CC5 is continuously orchestrated, and thenHARQ-ACK information for a transport block in a time unit in the firstpiece of DCI on the CC6 is orchestrated. Specifically, HARQ-ACKinformation for a transport block in a current time unit D(8,6) on theCC5 is orchestrated, and the HARQ-ACK information is located in the2^(nd) bit of the feedback information (a location corresponding to aC-DAI is

Lj + V_(C − DAI, c, m)^(DL) − N _(c, m)  = 2,

where

V_(C − DAI, c, m)  = 6,

N_( c, m)  = 4, L = 16, and j=0

). Because the DCI schedules four time units, four bits starting fromthe 2^(nd) bit are feedback information for data in the four time unitsscheduled by the DCI. On the CC4, a time unit in the first column is notscheduled, but a time unit in the second column is scheduled. Therefore,the terminal device needs to skip the CC4, and first orchestratesHARQ-ACK information for a transport block in a time unit in the firstpiece of DCI on the CC6. After orchestrating the time unit in the firstpiece of DCI on the CC6, the terminal device orchestrates HARQ-ACKinformation for a transport block in a time unit scheduled by DCI on theCC4. Finally, the terminal device orchestrates HARQ-ACK information fora transport block in a time unit in the second piece of DCI on the CC6.Then, in 11 bits, a location filled with no HARQ-ACK bit is set to NACK.To be specific, a location (the 1^(st) bit) corresponding to a C-DAI inthe DCI D(8.2) is a NACK because the DCI is not detected. Therefore, alocation corresponding to a C-DAI (the location corresponding to theC-DAI is

Lj + V_(C − DAI, c, m)^(DL) − N _(c, m)  = 1,

where

V_(C − DAI, c, m)  = 2, L = 16,  j = 0, andN_(c, m) = 1

) is filled with no HARQ-ACK bit. Specific location information is shownin FIG. 9 b .

In this manner, a variable quantity of time units actually scheduled byDCI needs to be considered during DAI statistics collection. To avoidunderstanding inconsistency between the transmit end and the receiveend, a bit quantity of the C-DAI/T-DAI field should be at least greaterthan log₂(N). For example, in the foregoing examples, it is assumed thatthe bit quantities of the C-DAI field and the T-DAI field are four bits,and therefore L=16. Otherwise, understanding inconsistency may be causedbetween the transmit end and the receive end. For example, it is assumedthat the C-DAI includes two bits, that a maximum quantity of time unitsscheduled by one piece of DCI is 8, that a C-DAI in the first piece ofDCI is 1 (00), and that a C-DAI in the second piece of DCI is 2 (01).Therefore, there are at least two possible cases: Case 1, only one timeunit is scheduled by each of the two pieces of DCI, and no packet lossoccurs. Case 2, the first piece of DCI schedules one packet, the secondpiece of DCI schedules one time unit, and one piece of DCI is lost,where the lost DCI schedules four time units. This manner can saveunnecessary feedback overheads, for example, a default value does notneed to be fed back in Manner 1.

Manner 4

In this manner, the time unit aggregation information includes whethertime unit aggregation is configured (or whether time aggregation isenabled). Based on whether carriers are configured with time unitaggregation, carriers in a carrier group (for example, a PUCCH carriergroup) are grouped into a carrier subset configured with time unitaggregation and a carrier subset configured without time unitaggregation. In other words, carriers configured with time unitaggregation are grouped into one subset, and carriers configured withouttime unit aggregation are grouped into another subset. Alternatively,the time unit aggregation information directly includes a carrier subsetconfigured with time unit aggregation and/or a carrier subset configuredwithout time unit aggregation.

For the carrier subset configured with time unit aggregation, theterminal device determines, based on a T-DAI corresponding to thecarrier subset configured with time unit aggregation and a maximumquantity of time units configured for the carrier subset, a bit quantityof feedback information for the carrier subset configured with time unitaggregation; and determines one piece of feedback information. Methodsfor determining the bit quantity and the feedback information have beendescribed in the foregoing manners (refer to any one of Manners 1 to 3or other possible manners, and this is not limited in this application),and details are not described again.

For the carrier subset configured without time unit aggregation, theterminal device determines, based on a T-DAI corresponding to thecarrier subset configured without time unit aggregation, a bit quantityof feedback information for the carrier subset configured without timeunit aggregation; and determines one piece of feedback information.Methods for determining the bit quantity and the feedback informationmay be similar to those in an LTE system (refer to the determiningmanner in the example shown in Table 2 or other possible manners, andthis is not limited in this application), and details are not describedagain.

The terminal device combines the feedback information for the carriersubset configured with time unit aggregation and the feedbackinformation for the carrier subset configured without time unitaggregation, to obtain final feedback information.

For example, as shown in FIG. 5 c , it is assumed that for a carrier 1to a carrier 6, multi-time-unit aggregation is enabled and/or aconfigured quantity of time units scheduled by one piece of DCI isgreater than 1, while for a carrier 7 to a carrier 10, multi-time-unitaggregation is disabled and/or a configured quantity of time unitsscheduled by one piece of DCI is equal to 1. Therefore, the CC1 to theCC6 are grouped into one subset. It is assumed that the feedbackinformation for this subset, determined in Manner 1, includes 24 bits(for details, refer to Manner 1), or that the feedback information forthis subset, determined in Manner 2, includes six bits (for details,refer to Manner 2), or that the feedback information for this subset,determined in Manner 3, includes 11 bits (for details, refer to Manner3); or the bit quantity of the feedback information may be determined inanother possible manner. In addition, the CC7 to the CC10 are groupedinto another subset, and the feedback information determined in an LTEmanner includes six bits (refer to the determining manner in the exampleshown in Table 2), or the bit quantity of the feedback information isdetermined in another possible manner. Then, the feedback informationfor the subset 1 and the feedback information for the subset 2 arecascaded to obtain final feedback information. The feedback informationfor the subset 1 may be placed before the feedback information for thesubset 2, or the feedback information for the subset 1 may be placedafter the feedback information for the subset 2.

In this manner, feedback information may be separately determined basedon a status of time unit aggregation configured on each carrier, to saveunnecessary DCI indication overheads and UCI feedback overheads.

It should be noted: 1. In this embodiment, only time unit aggregationinformation is discussed in subset grouping. In addition, other factorsmay also be considered, for example, whether CBG transmission/feedbackis configured, and/or, whether numerology or time unit duration isconfigured. Specifically, a carrier “configured with CBG feedback andconfigured with time unit aggregation” may be determined into onesubset, and a carrier “configured without CBG feedback and configuredwith time unit aggregation” may be determined into one subset, and acarrier “configured with CBG feedback and configured without time unitaggregation” may be determined into one subset; and a carrier“configured without CBG feedback and configured without time unitaggregation” may be determined into one subset. By way of example butnot limitation, for the subset “configured with CBG feedback andconfigured with time unit aggregation”, the bit quantity of the feedbackinformation is determined based on a maximum quantity of time units anda maximum CBG quantity; for the subset “configured without CBG feedbackand configured with time unit aggregation”, the bit quantity of thefeedback information is determined based on a maximum quantity of timeunits; and for the subset “configured with CBG feedback and configuredwithout time unit aggregation”, the bit quantity of feedback informationis determined based on a maximum CBG quantity. 2. The subsets may bedirectly and implicitly determined based on the time unit aggregationinformation, and therefore no additional signaling overheads arerequired. Certainly, for the purpose of flexibility, the transmit devicemay notify the receive device of a subset division result throughsignaling, that is, which carriers are determined into one subset.Signaling in this specification may be radio resource control (RRC)signaling, a master information block (MIB) message, a systeminformation block (SIB) message, radio resource control (RRC) signaling,media access control control element (MAC CE) signaling, or one or moretypes of physical layer signaling. Details are not described.

Manner 5

In this manner, the time unit aggregation information includes aquantity of aggregated time units configured for a carrier. The terminaldevice groups carriers in a carrier group (for example, a PUCCH carriergroup) into Z subsets based on the quantity of aggregated time unitsconfigured for a carrier, where configured quantities of aggregated timeunits on all carriers in one subset are the same. For example, carrierseach configured with four aggregated time units are grouped into onesubset, carriers each configured with two aggregated time units aregrouped into another subset, and carriers each configured with oneaggregated time unit are grouped into still another subset.

For the i^(th) subset of the Z subsets, the terminal device determines,based on a T-DAI for the i^(th) subset and a quantity of time unitsconfigured for the i^(th) subset, a bit quantity of feedback informationfor the i^(th) subset, that is, determines that a product of the T-DAIfor the i^(th) subset and the quantity of time units configured for thei^(th) subset is the bit quantity of the feedback information for thei^(th) subset (refer to any one of Manners 1 to 4 described above orother possible manners different from those in this application). Theterminal device orchestrates, based on C-DAI indication information inDCI in the i^(th) subset, HARQ-ACK information for a transport block ina time unit scheduled by the DCI, to the feedback information for thei^(th) subset (refer to any one of Manners 1 to 4 described above orother possible manners different from those in this application). Inother words, a location corresponding to the C-DAI indicationinformation in the feedback information for the i^(th) subsetcorresponds to the HARQ-ACK information for the transport block in thetime unit scheduled by the DCI in the i^(th) subset, so as to obtain thefeedback information for the i^(th) subset. Finally, the terminal devicecombines feedback information for the Z subsets to obtain final feedbackinformation. It should be noted that, a carrier or a subset that isconfigured without time unit aggregation or whose time unit aggregationis disabled may be understood as a carrier or a subset whose configuredquantity of time units is 1.

Manner 6

In this manner, the time unit aggregation information includes whethertime unit aggregation is configured, or whether a carrier is configuredwith or without time unit aggregation, and/or a quantity of aggregatedtime units configured for a carrier.

The receive end device determines, according to a dynamic codebookmechanism, feedback information for a carrier that is configured withouttime unit aggregation or whose configured quantity of aggregated timeunits is 1. In an implementation, the receive end device determines,based on the T-DAI indication information and the C-DAI indicationinformation, the feedback information for the carrier that is configuredwithout time unit aggregation or whose configured quantity of aggregatedtime units is 1. For details, refer to an LTE determining manner (fordetails, refer to the determining manner in the example shown in Table2) or another possible manner.

The receive end device determines, according to a semi-persistentcodebook mechanism, feedback information for a carrier that isconfigured with time unit aggregation and/or whose quantity ofaggregated time units configured for a carrier is greater than 1 (onepiece of feedback information may be determined for each carrier, andthen the feedback information for all carriers is combined; or one pieceof feedback information may be jointly determined). In animplementation, the receive end device determines, based on time windowinformation and in a semi-persistent manner, the feedback informationfor the carrier that is configured with time unit aggregation and/orwhose quantity of aggregated time units configured for a carrier isgreater than 1. The time window information may be determined based on aconfigured HARQ time sequence K1 set. Specifically, a size of thesemi-persistent codebook equals a size of the configured HARQ timesequence K1 set (or a time window size). It is assumed that a K1 setsemi-persistently configured through RRC is {3,4,5,6}, and it may bedetermined that the time window size is also 4. In other words, a sizeof feedback information for one carrier that is configured with timeunit aggregation and/or whose quantity of aggregated time unitsconfigured for a carrier is greater than 1 is four bits. Duringorchestration, optionally, the feedback information is orchestrated to acorresponding location in a chronological order. Determining feedbackinformation in a semi-persistent manner (or referred to as asemi-persistent codebook mechanism) means that, the size of thedetermined feedback information does not depend on a quantity of piecesof actually scheduled/transmitted data. Specifically, a locationcorresponding to a time unit in which a PDSCH (where a decoding resultfor the PDSCH is borne in the feedback information) is transmitted inthe time window is the decoding result for the corresponding PDSCH; anda location corresponding to a time unit in which no PDSCH is transmittedmay be a default value, for example, a NACK or DTX. It should be notedthat the foregoing manner is merely a possible semi-persistent manner ofdetermining feedback information, and another semi-persistent codebookdetermining manner is also applicable to this application. For example,refer to other embodiments hereinafter or other possible mannersdifferent from those in this application.

Then, the receive end device combines the two parts of feedbackinformation to obtain final feedback information.

It should be noted that the concept of the foregoing manner is alsoapplicable to CBG transmission. To be specific, the receive end devicedetermines, according to the dynamic codebook mechanism, feedbackinformation for a carrier that is configured without CBG feedback orwhose configured CBG quantity is 1. In an implementation, the receiveend device determines, based on the T-DAI indication information and theC-DAI indication information, the feedback information for the carrierthat is configured without CBG feedback or whose configured CBG quantityis 1. For details, refer to an LTE determining manner (for details,refer to the determining manner in the example shown in Table 2) oranother possible manner.

The receive end device determines, according to the semi-persistentcodebook mechanism, feedback information for a carrier that isconfigured with CBG feedback or whose configured CBG quantity is greaterthan 1. In an implementation, the receive end device determines, basedon the time window size and a configured CBG quantity, the feedbackinformation for the carrier that is configured with CBG feedback orwhose configured CBG quantity is greater than 1.

This manner can also ensure understanding consistency between thetransmit end and the receive end, support a flexible time unitaggregation configuration, and save unnecessary DCI overheads and UCIfeedback overheads.

It should be noted that, in all the embodiments of this application, thetime unit aggregation information may be borne through higher layersignaling (for example, RRC signaling or MAC CE), through physical layersignaling (for example (group) common DCI or UE-specific DCI), orthrough a combination of higher layer signaling and physical layersignaling (for example, one set is configured through RRC signaling, anda specific value or whether to enable/disable is indicated through DCI).

In another possible manner of this manner, signaling for configuring CBGfeedback/transmission and signaling for configuring time unitaggregation information are not the same one. Therefore, a carrier maybe configured with both CBG feedback/transmission and time unitaggregation information. In this case, all the configuration signalingcan be valid.

(1) In Manner 1, L bits (L is a configured maximum CBG quantity) are fedback for all TBs, that is, a feedback bit quantity is determined byT-DAI*N*L. An orchestration manner is similar. L bits for TBs scheduledby one piece of DCI may be sequentially arranged to locationscorresponding to a C-DAI or alternately arranged to locationscorresponding to a C-DAI. In other words, the L bits at the locationscorresponding to the C-DAI are sequentially arranged as the TBsscheduled by the one piece of DCI, and the L bits at the locationscorresponding to the C-DAI are alternately arranged as the TBs scheduledby the one piece of DCI. Certainly, feedback information of the maximumCBG quantity does not need to be fed back for every TB. This may besimilar to Manner 3, that is, a quantity of scheduled CBGs is equal to abit quantity of feedback information that needs to be fed back. However,in this case, the bit quantity of the C-DAI/T-DAI field should be atleast greater than log₂(NL).

(2) In Manner 2, L bits are fed back for a code word scheduled by eachpiece of DCI. To be specific, an AND operation is performed on feedbackinformation for all CBGs in a plurality of time units to generateone-bit feedback information. For example, the DCI schedules one codeword, which corresponds to X time units, and therefore one bit isgenerated by performing an AND operation on feedback information for thefirst CBG in the X time units, one bit is generated by performing an ANDoperation on feedback information for the second CBG in the X timeunits, and by analogy, L bits are generated. Alternatively, N bits arefed back for a code word scheduled by each piece of DCI. To be specific,one bit is generated by performing an AND operation on feedbackinformation for a plurality of CBGs in each of a plurality of timeunits. For example, the DCI schedules one code word, which correspondsto X time units, and therefore one bit is generated by performing an ANDoperation on feedback information for a plurality of CBGs in the 1^(st)time unit of the X time units, one bit is generated by performing an ANDoperation on feedback information for a plurality of CBGs in the 2^(nd)time unit of the X time units, and by analogy, N bits are generated.

(3) In Manner 3, L bits (L is a configured maximum CBG quantity) are fedback for all TBs, that is, a feedback bit quantity is determined byT-DAI*L. An orchestration manner is similar. L bits for TBs scheduled byone piece of DCI may be sequentially arranged to locations correspondingto a C-DAI or alternately arranged to locations corresponding to aC-DAI. In other words, the L bits at the locations corresponding to theC-DAI are sequentially arranged as the TBs scheduled by the one piece ofDCI, and the L bits at the locations corresponding to the C-DAI arealternately arranged as the TBs scheduled by the one piece of DCI.

Excessively high UCI or DCI overheads may be avoided in the followingmanners. 1. If a quantity of aggregated time units is set to be greaterthan 1 (or time unit aggregation is enabled), TB-level feedback is usedby default, instead of using/enabling CBG feedback/transmission,although signaling is used to configure the CBG feedback/transmission.In this manner, it may be understood that time unit aggregation has ahigher priority than CBG feedback/transmission. 2. If CBG transmissionis configured, a quantity of aggregated time units is set to 1 bydefault (or time unit aggregation is disabled), although signaling isused to configure the quantity of aggregated time units to be greaterthan 1 (or time unit aggregation is enabled). In this manner, it may beunderstood that time unit aggregation has a lower priority than CBGfeedback/transmission.

In a case of CBG transmission configured, if one piece of DCI schedulesa plurality of time units, the DCI may include the following content:

1. One CBG indication (a bit quantity depends on a quantity of CBGconfigured through RRC signaling). The one CBG indication is used toindicate which CBG transmission is scheduled. A plurality of time unitsscheduled by the DCI share one CBG indication. For example, a four-bitCBG indication is 1101. This means that the 1^(st) time unit schedules aCBG1, a CBG2, and a CBG4; the 2^(nd) time unit schedules the CBG1, theCBG2, and the CBG4; and by analogy, the X^(th) time unit schedules theCBG1, the CBG2, and the CBG4. Certainly, the DCI may include two CBGindications, which correspond to indications of two code words. DCIoverheads can be lower than those in a case of X or N CBG indications.

2. One flush indication (for example, one bit). The one flush indicationis used to indicate that a currently scheduled CBG or data bufferrequires special processing (for example, receiving a data buffer beforeflushing and/or not participating in HARQ combination). A plurality oftime units scheduled by the DCI share one flush indication indication.For example, a one-bit flush indication is 1. This means that a CBG/databuffer scheduled by the 1^(st) time unit is flushed and does notparticipate in HARQ combination, a CBG/data buffer scheduled by the2^(nd) time unit is flushed and does not participate in HARQcombination, and by analogy, a CBG/data buffer scheduled by the X^(th)time unit is flushed and does not participate in HARQ combination.Certainly, the DCI may include two flush indications, which correspondto indications of two code words, or the DCI still includes one flushindication (for example, one bit), and the one flush indication is usedto indicate processing of two code words. DCI overheads can be lowerthan those in a case of X or N CBG indications.

Step 203: The terminal device sends the feedback information for the atleast one transport block.

According to the foregoing embodiment, the terminal device obtains thetime unit aggregation information and the DAI indication informationthat are sent by the base station, determines the feedback informationfor the at least one transport block based on the time unit aggregationinformation and the DAI indication information, and finally sends thefeedback information for the at least one transport block to the basestation. This can improve a manner of determining HARQ feedbackinformation in an NR system, so as to support a scenario with a flexiblequantity of aggregated/scheduled time units, thereby avoidingunderstanding inconsistency and disorder of the HARQ feedbackinformation between the terminal device and the base station on apremise of ensuring downlink control overheads and uplink feedbackoverheads.

Based on the same technical concept, the following further providesother embodiments to describe the procedure of determining feedbackinformation in this application.

Embodiment 2

Because a base station may further configure, for a terminal device, oneor more bandwidth parts (BWPs) on one carrier, each BWP corresponds toone type of numerology, for example, a subcarrier spacing, a cyclicprefix (CP), or another parameter. Therefore, in a possibleimplementation of this application, feedback information may bedetermined based on BWPs that are configured or activated or that can besimultaneously activated on the carrier.

Specifically, there may be two manners: a dynamic codebook manner and asemi-persistent codebook manner.

For the dynamic codebook manner, refer to a procedure shown in FIG. 10 .The procedure may specifically include the following steps.

Step 1001: A receive end device obtains control information sent by atransmit end device, where the control information includes BWPinformation and DAI information, and the DAI information includes atleast one type of T-DAI indication information and C-DAI indicationinformation.

In a possible implementation of this application, the controlinformation may include the BWP information (for example, BWPs that areconfigured or activated or that can be simultaneously activated, oractivation/deactivation signaling for the BWP and/or BWP configurationinformation). Second control information may include the T-DAIindication information and the C-DAI indication information. Fordefinitions of a T-DAI and a C-DAI, refer to the foregoing descriptions.A difference lies in that the T-DAI/C-DAI is counted in the followingorder: CCs, BWPs, and time units. For example, refer to Table 4.

TABLE 4 CC1,BWP1 D(4,1) CC2,BWP1 CC2,BWP2 D(4,2) CC2,BWP3 D(4,3)CC3,BWP1 D(5,5) CC3,BWP2 D(4,4) D(6,6)

Step 1002: The receive end device determines feedback information basedon the T-DAI indication information and the C-DAI indicationinformation.

In the process of determining the feedback information, time unitaggregation information may be considered. For details, refer to Manners1 to 6. If no time unit aggregation is configured, refer to thedescriptions of the determining manner in the example shown in Table 2.Details are not described herein again.

Step 1003: The receive end device sends the feedback information to thetransmit end device.

In the semi-persistent codebook manner, the BWP aggregation informationmay be a quantity of BWPs that are configured or activated or that canbe simultaneously activated on the carrier. The terminal determines abit quantity of the feedback information based on the BWP aggregationinformation and a time window size.

For example, it is assumed that there are three carriers, a quantity ofBWPs on a first carrier is 2, a quantity of BWPs on a second carrier is1, and a quantity of BWPs on a third carrier is 3. The time window sizeis 2. Therefore, the feedback bit quantity is (2+1+3)*2=12 bits. Anarrangement order of feedback information for all carriers may be asfollows:

Arrangement manner 1: Feedback information for all carriers issequentially arranged, as shown in FIG. 11 .

Arrangement manner 2: Feedback information for all BWPs is sequentiallyarranged, as shown in FIG. 12 .

Arrangement manner 3: Feedback information is arranged first infrequency domain and then in time domain, as shown in FIG. 13 .

Embodiment 3

In this embodiment, feedback information is determined based on timewindow information and time unit format information (slot formatinformation, SFI). In an implementation, the time window information maybe determined based on a set of configured possible values of K1, andthe SFI is borne in higher layer signaling (for example, RRC signaling)and/or physical layer signaling (for example, group common DCI).

In an NR system, to support flexible and dynamic TDD, a DL/ULtransmission direction of each time unit (a slot, a symbol, and thelike) may be configured through higher layer signaling and/or physicallayer group common DCI. In a possible implementation, one period isconfigured, for example, a time duration for the period is 5 ms or 10ms. Within this period, some fixed resources/time units may beconfigured for UL transmission, other fixed resources/time units may beconfigured for DL transmission, and some reserved resources may beconfigured; and the remaining resources/time units within the period maybe flexibly and dynamically designated as DL or UL or reserved/blankresources.

For example, as shown in FIG. 14 , time units 0 to 2 are fixedly usedfor DL transmission, time units 7 to 9 are fixedly used for ULtransmission, and time units 3 to 6 may be flexibly and dynamicallydesignated as DL or UL or reserved/blank resources. The period includes10 time units. FIG. 14 clearly shows that the time units fixedlyconfigured for UL should not be present in a time window or feedbackinformation. Therefore, when the terminal device determines the feedbackinformation based on the time window configured by a base station, aDL/UL transmission direction for a time unit further needs to beconsidered, thereby avoiding unnecessary feedback overheads.

It is assumed that a K1 set semi-persistently configured through RRC is{3,4,5,6}. A TB that is possibly fed back in an uplink time unit #7comes from a downlink time unit #1 (n+6), a downlink time unit #2 (n+5),a downlink time unit #3 (n+4), and a downlink time unit #4 (n+3).Therefore, the time window includes the time units #1 to #4, and it maybe determined that a bit quantity of feedback information is four bits.A TB that is possibly fed back in an uplink time unit #9 comes from adownlink time unit #3 (n+6), a downlink time unit #4 (n+5), a downlinktime unit #5 (n+4), and a downlink time unit #6 (n+3). Therefore, thetime window includes the time units #3 to #6, and it may be determinedthat a bit quantity of feedback information is four bits. It should benoted that, if K1 indication information in DCI that schedules a PDSCHtransmitted in a specific time unit is not fed back in the time unit #7,a corresponding bit may be optionally set to NACK or DTX. For example,it is assumed that K1 indication information in DCI that schedules aPDSCH in the time unit #2 is not 5 (not fed back in the time unit #7),and a corresponding bit may be optionally set to NACK or DTX in thefeedback information.

If the time unit #3 is fixedly configured for uplink transmission,feedback information fed back in the uplink time unit #7 does not needto include the time unit #3, and correspondingly the terminal device maydetermine that the bit quantity of the feedback information is threebits. Feedback information fed back in the uplink time unit #9 does notneed to include the time unit #3, and correspondingly the terminaldevice may determine that the bit quantity of the feedback informationis three bits. In other words, in the process of determining the bitquantity of the feedback information, whether a time unit in the timewindow is configured for uplink transmission or downlink transmissionneeds to be detected. If uplink transmission is included (which may befixed uplink transmission semi-persistently configured through higherlayer signaling and/or uplink transmission dynamically indicated byphysical layer signaling), the uplink transmission (which may be fixeduplink transmission semi-persistently configured through higher layersignaling and/or uplink transmission dynamically indicated by physicallayer signaling) needs to be excluded, and only feedback information fora transport block in a corresponding time unit configured for downlinktransmission needs to be fed back. In this manner, a feedbackcorresponding to an uplink transmission time unit is excluded, therebysaving unnecessary feedback overheads.

In the foregoing example, only the uplink transmission time unit isconsidered. Similarly optionally, a feedback corresponding to areserved/blank time unit may be further excluded.

In the foregoing example, the time window is determined by theconfigured set of possible values of K1. In addition, the time windowmay be directly configured through signaling. In an implementation, RRCconfiguration signaling may be used to configure a time window sizeand/or a minimum value of K1; a distance between the last time unit inthe time window and a time unit of a PUCCH/PUSCH bearing the feedbackinformation and/or a maximum value of K1; and a distance between the1^(st) time unit in the time window and a time unit of a PUCCH/PUSCHbearing the feedback information. In this manner, the time window can beflexibly managed/configured.

As shown in FIG. 15 , a time window size is set to 4, a minimum value ofa time window K1 is set to 2, and therefore a codebook size fed back ina time unit 10 is 4, which corresponds to transmission in time units 4to 7. The foregoing configuration may be configured for each time unitand/or may be configured for each carrier, or only one configuration(all time units and all carriers share the one configuration) may beconfigured for UE.

In addition, other manners of determining a time window are alsoapplicable, and this is not limited in this application.

Embodiment 4

In a possible implementation, in 5G, a period of a control channelresource or a PDCCH for DCI that schedules a PDSCH of each carrier isconfigurable. Therefore, a monitoring period may be considered asfollows: For example, monitoring is performed once at intervals of onetime-domain symbol or a plurality of time-domain symbols or at intervalsof one time unit or a plurality of time units. It is assumed that a samequantity of symbols or time units is configured, if a subcarrier spacingconfiguration or a numerology configuration is different, periods mayalso be considered to be different.

To simplify a design of a DAI borne in DCI (for example, to makecounting simpler, or otherwise time misalignment and complex countingmay be caused), in the foregoing process of grouping carrier subsets, aterminal device may further obtain subsets through grouping based on themonitoring period of the control channel or the control channelresource. Specifically, the terminal device groups carriers into Msubsets based on the monitoring period of the control channel or thecontrol channel resource, and monitoring periods of control channels orcontrol channel resources of carriers in one subset are the same. Forexample, some carriers are grouped into a subset 1, and a monitoringperiod of a control channel or a control channel resource or a controlresource set (CORESET) bearing DCI that schedules a PDSCH on the carrieris 1; and some carriers are grouped into a subset 2, and a monitoringperiod of a control channel or a control channel resource or a CORESETbearing DCI that schedules a PDSCH on the carrier is 2.

For the i^(th) subset of the M subsets, the terminal device maydetermine one piece of feedback information based on the foregoingembodiments or other possible embodiments different from those in thisapplication, and then the terminal device combines feedback informationfor the M subsets to obtain final feedback information. Details are notdescribed.

Embodiment 5

In a possible implementation, in a manner of collecting statistics of aT-DAI and a C-DAI based on subsets (for example, as described in theforegoing embodiments) or carriers, if DCI on a specific carrier islost, understanding inconsistency may be caused between a base stationand a terminal device, causing poor robustness of a system. As shown inFIG. 16 , if DCI D(3,3) is lost, the last received T-DAI is 2 for afirst subset, and the last received T-DAI is 7 for a second subset. In acase with only one code word configured and CBG unconfigured, the UEfeeds back nine (2+7) bits. However, the base station requires theterminal device to feed back 10 (3+7) bits. Consequently, understandinginconsistency is caused between the base station and the terminaldevice, and the base station cannot receive HARQ information fed back bythe terminal device.

In view of this, this embodiment provides a manner ofcarrier-group-based T-DAI statistics collection and subset-based C-DAIstatistics collection. Refer to FIG. 17 (the left diagram of FIG. 17shows that the T-DAI indicates a total quantity of scheduled PDSCHscounted in a current shortest time unit; and the right diagram of FIG.17 shows that the T-DAI indicates a total quantity of scheduled PDSCHswithin a current longest time unit). The T-DAI is specific to statisticscollection of all six carriers in a carrier group (for example, a PUCCHcarrier group). For a physical meaning, refer to the foregoingdescriptions. The C-DAI is specific to statistics collection of carriersincluded in a subset in a carrier group (for example, a PUCCH carriergroup). For a physical meaning, refer to the foregoing descriptions.

As shown in FIG. 17 , statistics show that a total T-DAI of allscheduled subsets in a carrier group is 10, where a C-DAI for a firstsubset is 3, and a C-DAI for a second subset is 7. In a case with onecode word configured and CBG feedback unconfigured, the terminal deviceknows that 10-bit feedback information needs to be generated, wherethree bits thereof are placed as feedback information for the firstsubset, and seven bits thereof are placed as feedback information forthe second subset.

In addition, in this application, it is assumed that there are Nsubsets, and feedback information for first (N-1) subsets issequentially cascaded and is orchestrated in order starting from thefirst bit of total feedback information, while feedback information forthe N^(th) subset is orchestrated in reverse order starting from thelast bit of the total feedback information. As shown in Table 5, threebits of the first subset are sequentially orchestrated to first threebits of the total feedback information (10 bits) (HARQ-ACK informationfor a TB corresponding to D(4,1) is the 1^(st) bit, HARQ-ACK informationfor a TB corresponding to D(4,2) is the 2^(nd) bit, and so on). Theseven bits of the second subset are orchestrated to the end of the totalfeedback information in reverse order (HARQ-ACK information for a TBcorresponding to D(4,1) is the 10^(th) bit, HARQ-ACK information for aTB corresponding to D(4,2) is the 9^(th) bit, and so on).

TABLE 5 A/N A/N A/N A/N A/N A/N A/N A/N A/N A/N D(4,1) D(4,2) D(9,3)D(10,7) D(9,6) D(7,5) D(6,4) D(5,3) D(4,2) D(4,1)

Alternatively, as shown in Table 6, three bits of the first subset aresequentially orchestrated to first three bits of the total feedbackinformation (10 bits) (HARQ-ACK information for a TB corresponding toD(7,1) is the 1^(st) bit, HARQ-ACK information for a TB corresponding toD(7,2) is the 2^(nd) bit, and so on). The seven bits of the secondsubset are orchestrated to the end of the total feedback information inreverse order (HARQ-ACK information for a TB corresponding to D(7,1) isthe 10^(th) bit, HARQ-ACK information for a TB corresponding to D(7,2)is the 9^(th) bit, and so on).

TABLE 6 A/N A/N A/N A/N A/N A/N A/N A/N A/N A/N D(7,1) D(7,2) D(10,3)D(10,7) D(10,6) D(7,5) D(7,4) D(7,3) D(7,2) D(7,1)

It should be noted that, feedback information for the first subset maybe alternatively orchestrated in order starting from the 1^(st) bit ofthe total feedback information, and feedback information for last (N-1)subsets is orchestrated in reverse order starting from the last bit ofthe total feedback information. This embodiment is merely an example,and an orchestration order of feedback information for each subset isnot limited.

Therefore, in FIG. 17 , it is assumed that DCI D(9,3) is lost, theterminal device still generates 10-bit feedback information, and thebase station can correctly extract 10-bit feedback information from the10-bit feedback information fed back by the terminal device. However, inthe prior art, only nine bits are generated, incorrect mapping occursfrom the 3^(rd) bit. The 3^(rd) bit should correspond to HARQ-ACKinformation for the last one TB of the first subset. However, the 3^(rd)bit fed back by the terminal device is HARQ-ACK information for thefirst TB of the second subset. Therefore, this embodiment can enhancerobustness of the feedback information.

Similarly, in this embodiment, a manner of carrier-group-based C-DAIstatistics collection and subset-based T-DAI statistics collection maybe alternatively used, and details are not described.

Embodiment 6

Feedback information is determined based on numerology (or time unitduration) of each carrier or BWP and based on a time window size.Specifically, if HARQ feedback information on a first carrier is borneon an uplink control channel on a second carrier for transmission, asize of the HARQ feedback information on the first carrier is the timewindow size (for example, a quantity of values in an RRC-configured timewindow K1 set)*N, where N=Time unit duration of the second carrier/Timeunit duration of the first carrier (or N=Subcarrier spacing of the firstcarrier/Subcarrier spacing of the second carrier, or time units of Nfirst carriers are aligned with a time unit of one second carrier).

For example, if an RRC-configured K1 set is {1,2}, a size of theRRC-configured time window K1 set is 2. As shown in FIG. 18 , Time unitduration of a second carrier/Time unit duration of a first carrier=2 (orSubcarrier spacing of the first carrier/Subcarrier spacing of the secondcarrier=2, or time units of two first carriers are aligned with a timeunit of one second carrier), and therefore, a size of HARQ feedbackinformation for the first carrier is 2*2=4.

As shown in FIG. 19 , Time unit duration of a second carrier/Time unitduration of a first carrier=½ (or Subcarrier spacing of the firstcarrier/Subcarrier spacing of the second carrier=½, or a time unit ofone first carrier is aligned with time units of two second carriers),and therefore, a size of HARQ feedback information for the first carrieris 2*½=1.

It should be noted that if N<1, the result may be obtained through roundup.

If time unit aggregation is considered, after one TB is mapped into aplurality of aggregated time units, it may be understood that time unitduration increases, in other words, Time unit duration=Duration of onetime unit*Quantity of time units.

Certainly, with reference to the foregoing embodiments, a quantity offixed uplink time units on the carrier in a time window may be furtherexcluded.

Another possible implementation is as follows:

Feedback information is determined based on a DAI, K2, and a timewindow. K2 represents a time relationship between a time unit fortransmitting a PDCCH and a time unit for transmitting a PUSCH, where thePDCCH is used for scheduling the PUSCH. Specifically, if schedulinginformation is sent on the PDCCH in the n^(th) time unit,correspondingly, a time unit used by the PUSCH is the (n+K2)^(th) timeunit.

For a semi-persistent codebook, a codebook size is the time window size.For example, the time window size is M time units, and in a case of onecarrier, a single code word configured, and a CBG unconfigured, the sizeof the semi-persistent codebook is M bits (not depending on a quantityof actually scheduled PDSCHs). To save feedback overheads, there may beDCI that schedules a PUSCH in the last time unit in the time window,where the DCI may carry a DAI indication, to indicate the quantity ofactually scheduled PDSCHs in the time window. Therefore, the codebooksize fed back by UE may be less than M, and the feedback information maybe borne on the scheduled PUSCH to be fed back to the base station. InLTE, an interval between a time unit for scheduling DCI and a time unitfor transmitting a PUSCH is fixed (for example, 4). In addition, theinterval equals an interval between a time unit of the last PDSCH timeunit and a time unit for feeding back HARQ-ACK for the last PDSCH.Therefore, a time unit of DCI that schedules a PUSCH bearing a HARQ-ACKis definitely the last time unit in the time window.

Due to introduction of a flexible time sequence, to be specific, aninterval between a time unit for scheduling the DCI and a time unit fortransmitting a PUSCH is K2, which is flexible and variable (for example,for K0 and K1 as described in background, a set of possible values arefirst configured through RRC signaling, and then specific valueinformation is notified by using DCI). Therefore, the time unit of theDCI that schedules the PUSCH bearing the HARQ-ACK is not necessary thelast time unit in the time window. As shown in FIG. 20 , in this case,the DAI of the time unit of the DCI that schedules the PUSCH bearing theHARQ-ACK indicates a quantity of scheduled PDSCHs/time units that end ata current location. Therefore, the codebook size should be determined byDAI+X, where the DAI is the quantity of scheduled PDSCHs/time units thatend at the current location, and X is a size of a subwindow 2 in FIG. 20or a quantity of remaining time units in the time window (which isrelated to K2, and may be understood that Quantity of remaining timeunits=Value of K2-Configured minimal value of K1).

Such a manner can support a flexible K2 time sequence, thereby avoidingunnecessary feedback overheads.

It may be understood that, some technical descriptions, technicalhypotheses, and technical terms in the foregoing embodiments may beshared by all the foregoing embodiments, and technical solutions mayalso be combined, unless otherwise specified or the logic does not makesense. Details are not described.

Based on a same technical concept, an embodiment of this applicationfurther provides a terminal device. For a location of the terminaldevice in a communications system, refer to the terminal device shown inFIG. 1 The terminal device may be a mobile phone, a tablet computer, acomputer with a wireless transmission/reception function, a virtualreality terminal device, an augmented reality terminal device, awireless terminal in industrial control, a wireless terminal inself-driving, a wireless terminal in telemedicine, a wireless terminalin a smart grid, a wireless terminal in transportation safety, awireless terminal in a smart city, a wireless terminal in a smart home,or the like

Specifically, FIG. 21 shows a terminal device 21 according to anembodiment of this application. The terminal device 21 includes atransceiver 2108 and a processor 2104.

The terminal device 21 may further include a memory 2119, and the memory2119 stores a computer-executable instruction.

The transceiver 2108 is configured to: obtain control information sentby a transmit end device, where the control information includes timeunit aggregation information and downlink assignment index DAIindication information, and the DAI information includes at least onetype of total downlink assignment index T-DAI indication information andcounter downlink assignment index C-DAI indication information; and sendthe feedback information to the transmit end device;

-   the processor 2104 is configured to determine feedback information    for at least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver 2108; and-   the transceiver 2108 is further configured to send the feedback    information for the at least one transport block to the transmit end    device.

Further, the time unit aggregation information includes a maximumquantity of time units that can be scheduled by one piece of downlinkcontrol information DCI; and

-   when the processor 2104 determines the feedback information for the    at least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver 2108, the processor 2104 is specifically configured    to:-   determine a bit quantity of the feedback information for the at    least one transport block based on the T-DAI indication information    and the maximum quantity of time units that can be scheduled by one    piece of DCI; and-   orchestrate, based on the C-DAI indication information, feedback    information for a transport block in a time unit scheduled by the    DCI, to a location corresponding to the C-DAI indication    information.

Further, the time unit aggregation information includes a quantity oftime units scheduled by the DCI; and

-   when the processor 2104 determines the feedback information for the    at least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver 2108, the processor 2104 is specifically configured    to:    -   when a plurality of time units are scheduled by one piece of        DCI, perform an AND operation on feedback information for        transport blocks in the plurality of time units to generate        one-bit feedback information, and orchestrate the one-bit        feedback information to a location corresponding to a C-DAI in        the DCI; and    -   determine the bit quantity of the feedback information for the        at least one transport block based on the T-DAI indication        information.

The processor 2104 may be configured to execute actions internallyimplemented by the terminal device described in the foregoing methodembodiments, and the transceiver 2108 may be configured to execute atransmission or sending action from the terminal device to a basestation described in the foregoing method embodiments. For details,refer to the descriptions in the foregoing method embodiments. Detailsare not described herein again.

The processor 2104 and the memory 2119 may be integrated into oneprocessing apparatus. The processor 2104 is configured to executeprogram code stored in the memory 2119 to implement the foregoingfunctions. During specific implementation, the memory 2119 may bealternatively integrated into the processor 2104.

The terminal device may further include a power supply 2112, configuredto supply power to various components or circuits of the terminaldevice. The terminal device may include an antenna 2110, configured tosend, through a radio signal, uplink data or uplink control signalingthat is output by the transceiver 2108.

In addition, to improve functions of the terminal device, the terminaldevice may further include one or more of an input unit 2114, a displayunit 2116, an audio circuit 2118, a camera 2120, and a sensor 2122. Theaudio circuit may further include a speaker 21182, a microphone 21184,and the like.

The terminal device provided in this embodiment of this applicationobtains the time unit aggregation information and the DAI indicationinformation that are sent by the base station, determines the feedbackinformation based on the time unit aggregation information and the DAIindication information, and finally sends the feedback information tothe base station. This can improve a manner of determining HARQ feedbackinformation in an NR system, so as to support a scenario with a flexiblequantity of aggregated/scheduled time units, thereby avoidingunderstanding inconsistency and disorder of the HARQ feedbackinformation between the terminal device and the base station on apremise of ensuring downlink control overheads and uplink feedbackoverheads.

Optionally, when the processor 2104 determines the bit quantity of thefeedback information for the at least one transport block based on theT-DAI indication information and the maximum quantity of time units thatcan be scheduled by one piece of DCI, the processor 2104 is specificallyconfigured to:

determine that a product of the T-DAI indication information and themaximum quantity of time units that can be scheduled by one piece of DCIis the bit quantity of the feedback information for the at least onetransport block.

The terminal device obtains the bit quantity of the feedback informationbased on the product of the T-DAI indication information and the maximumquantity of time units that is configured for a carrier and that can bescheduled by one piece of DCI, so that DCI overheads can be reduced anddisorder of feedback information is avoided through multi-time-unitscheduling.

Optionally, when the processor 2104 orchestrates the feedbackinformation for the transport block in the time unit scheduled by theDCI, to the location corresponding to the C-DAI indication information,the processor 2104 is specifically configured to:

-   when the maximum quantity of time units that can be scheduled by one    piece of DCI is N, and a quantity of time units scheduled by one    piece of DCI is X, where X is an integer greater than or equal to 1    and less than or equal to N,-   orchestrate the feedback information for the transport block in the    time unit scheduled by the DCI, to first X bits at the location    corresponding to the C-DAI indication information, and set (N-X)    bits following the first X bits to default values.

The foregoing arrangement manner of the feedback information can ensureunderstanding consistency between the terminal device and the basestation in the scenario of supporting a flexible quantity of aggregatedtime units, thereby avoiding disorder of the feedback information.

Optionally, the time unit aggregation information includes a quantity oftime units scheduled by the DCI; and

-   when the processor 2104 determines the feedback information for the    at least one transport block based on the time unit aggregation    information and the DAI indication information that are obtained by    the transceiver 2108, the processor 2104 is specifically configured    to:-   determine the bit quantity of the feedback information for the at    least one transport block based on the T-DAI indication information;    and-   if a quantity of time units scheduled by one piece of DCI is Y,    orchestrate, based on the C-DAI indication information, feedback    information for transport blocks in the Y time units scheduled by    the DCI, to Y bits at the location corresponding to the C-DAI    indication information, where Y is an integer greater than or equal    to 1.

The foregoing arrangement manner of the feedback information can furtherensure understanding consistency between the transmit end and thereceive end in the scenario of supporting a flexible quantity ofaggregated time units, thereby avoiding disorder of the feedbackinformation.

Optionally, the time unit aggregation information includes a carriersubset configured with time unit aggregation and/or a carrier subsetconfigured without time unit aggregation; and

when the processor 2104 determines the feedback information for the atleast one transport block based on the time unit aggregation informationand the DAI indication information that are obtained by the transceiver2108, the processor 2104 is specifically configured to:

-   determine, based on a T-DAI corresponding to the carrier subset    configured with time unit aggregation and a maximum quantity of time    units configured for the carrier subset, a bit quantity of feedback    information for the carrier subset configured with time unit    aggregation;-   orchestrate, based on C-DAI indication information in DCI in the    carrier subset configured with time unit aggregation, feedback    information for a transport block in a time unit scheduled by the    DCI, to the feedback information for the carrier subset configured    with time unit aggregation; and/or-   determine, based on a T-DAI corresponding to the carrier subset    configured without time unit aggregation, a bit quantity of feedback    information for the carrier subset configured without time unit    aggregation; and-   orchestrate, based on C-DAI indication information in DCI in the    carrier subset configured without time unit aggregation, feedback    information for a transport block in a time unit scheduled by the    DCI, to the feedback information for the carrier subset configured    without time unit aggregation; and cascade the feedback information    for the carrier subset configured with time unit aggregation and the    feedback information for the carrier subset configured without time    unit aggregation.

Whether a carrier is configured with time unit aggregation is consideredduring carrier grouping, and therefore feedback information may beseparately determined based on a configuration status of time unitaggregation on each carrier, thereby saving unnecessary DCI indicationoverheads and UCI feedback overheads.

Optionally, the time unit aggregation information includes a quantity ofaggregated time units configured for a carrier; and

when the processor 2104 determines the feedback information for the atleast one transport block based on the time unit aggregation informationand the DAI indication information that are obtained by the transceiver2108, the processor 2104 is specifically configured to:

-   group carriers into Z subsets based on the quantity of aggregated    time units configured for a carrier, where configured quantities of    aggregated time units on all carriers in one subset are the same;    and-   for the i^(th) subset of the Z subsets, determine a bit quantity of    feedback information for the i^(th) subset based on a T-DAI for the    i^(th) subset and a quantity of time units configured for the i^(th)    subset; orchestrate, based on C-DAI indication information in DCI in    the i^(th) subset, feedback information for a transport block in a    time unit scheduled by the DCI, to feedback information for each    subset, where i is greater than or equal to 1 and less than or equal    to Z; and combine Z pieces of feedback information for the Z    subsets, where Z is greater than or equal to 1.

Carriers are grouped into subsets based on information about a quantityof aggregated time units configured on each carrier, and feedbackinformation is separately determined, thereby saving unnecessary DCIindication overheads and UCI feedback overheads.

Optionally, the time unit aggregation information includes whether acarrier is configured with or without time unit aggregation and/orincludes a quantity of aggregated time units configured for a carrier;and

when the processor 2104 determines the feedback information for the atleast one transport block based on the time unit aggregation informationand the DAI indication information that are obtained by the transceiver2108, the processor 2104 is specifically configured to:

-   determine, based on the T-DAI indication information and the C-DAI    indication information, feedback information for a carrier that is    configured without time unit aggregation or whose configured    quantity of aggregated time units is 1; and-   determine, based on a time window size, feedback information for a    carrier that is configured with time unit aggregation and/or whose    quantity of aggregated time units configured for a carrier is    greater than 1.

The foregoing embodiment can ensure understanding consistency betweenthe terminal device and the base station, support a flexible time unitaggregation configuration, and save unnecessary DCI overheads and UCIfeedback overheads.

An embodiment of this application further provides a network device. Fora location of the network device in a communications system, refer tothe base station in FIG. 1 . The network device may be a deviceconfigured to communicate with a terminal device. The network device maybe a base station or may be a wireless controller in a cloud wirelessaccess network scenario, or the network device may be a relay station,an access point, an in-vehicle device, a wearable device, a networkdevice in a future 5G network, a network device in a future evolved PLMNnetwork, or the like.

FIG. 22 shows a network device 22 according to an embodiment of thisapplication. The network device 22 includes at least a transceiver 2208and a processor 2204.

The network device 22 may further include a memory 2203, and the memory2203 stores a computer-executable instruction;

-   the processor 2204 is configured to control the transceiver 2208 to    send control information to a receive end device, where the control    information includes time unit aggregation information and/or    downlink assignment index DAI indication information, and the DAI    indication information includes at least one type of total downlink    assignment index T-DAI indication information and counter downlink    assignment index C-DAI indication information; and-   the processor 2204 is further configured to control the transceiver    2208 to receive feedback information sent by the receive end device    for at least one transport block, where the feedback information is    feedback information generated by the receive end device based on    the control information.

The processor 2204 and the memory 2203 may be integrated into oneprocessing apparatus. The processor 2204 is configured to executeprogram code stored in the memory 2203 to implement the foregoingfunctions.

The network device may further include an antenna 2210, configured tosend, through a radio signal, downlink data or downlink controlsignaling that is output by the transceiver 2208.

It should be noted that each of the processor 2104 of the terminaldevice and the processor 2204 of the network device may be a centralprocessing unit (CPU), a network processor (NP), or a combination of aCPU and an NP. The processor may further include a hardware chip. Thehardware chip may be an application-specific integrated circuit (ASIC),a programmable logic device (PLD), or a combination thereof. The PLD maybe a complex programmable logic device (CPLD), a field-programmablelogic gate array (FPGA), a generic array logic (GAL), or any combinationthereof.

Each of the memory 2119 of the terminal device and the memory 2203 ofthe network device may include a volatile memory, for example, a randomaccess memory (RAM); and may further include a non-volatile memory, forexample, a flash memory, a hard disk drive (HDD), or a solid-state drive(SSD). The memory may further include a combination of the foregoingtypes of memories.

The solutions described in the embodiments of the terminal device inFIG. 21 and the network device in FIG. 22 can resolve the foregoingtechnical problem, thereby avoiding disorder and understandinginconsistency of HARQ feedback information between a receive end deviceand a transmit end device. This embodiment of this application furtherprovides other implementations. For example, any one of implementationsin Embodiment 2 to Embodiment 6 can be applied to the base station andthe terminal device. For specific descriptions herein, refer to thedescriptions in Embodiment 2 to Embodiment 6. Details are not describedagain.

This application further provides a communications system. As shown inFIG. 1 , the communications system includes any terminal device as shownin FIG. 21 and described in detailed descriptions in the correspondingembodiment, and any network device as shown in FIG. 22 and described indetailed descriptions in the corresponding embodiment.

The network device in this apparatus embodiment of this application maybe corresponding to the base stations in method Embodiment 1 toEmbodiment 6 of this application, and the terminal device may becorresponding to the terminal devices in method Embodiment 1 toEmbodiment 6 of this application. In addition, the foregoing and otheroperations and/or functions of the modules of the network device and theterminal device are respectively used to implement correspondingprocedures in Embodiment 1 to Embodiment 6. For brevity, thedescriptions of the method embodiments of this application areapplicable to the apparatus embodiment. Details are not described hereinagain.

A person of ordinary skill in the art may be aware that, the units andalgorithm steps in the examples described with reference to theembodiments disclosed in this specification may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraints of thetechnical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of this application.

It may be clearly understood by a person skilled in the art that, forconvenience and brevity, for a detailed working process of the system,apparatus, and unit, reference may be made to a corresponding process inthe method embodiments. Details are not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electrical, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units may be integrated into one unit.

When the functions are implemented in a form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of this application essentially,or the part contributing to the prior art, or some of the technicalsolutions may be implemented in a form of a software product. Thecomputer software product is stored in a storage medium, and includesseveral instructions for instructing a computer device (which may be apersonal computer, a server, a network device, or the like) to performall or some of the steps of the methods described in the embodiments ofthis application. The foregoing storage medium includes any medium thatcan store program code, such as a USB flash drive, a removable harddisk, a read-only memory (ROM), a random access memory (RAM), a magneticdisk, or an optical disc.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thisapplication shall fall within the protection scope of this application.Therefore, the protection scope of this application shall be subject tothe protection scope of the claims.

What is claimed is:
 1. A method for processing feedback information, themethod comprising: sending a set of hybrid automatic repeat request(HARQ) time sequence K1 values and time unit format information, whereina HARQ time sequence K1 value of the set of HARQ time sequence K1 valuesis a time relationship between a time unit of a physical downlink sharedchannel (PDSCH) and a time unit of a physical uplink control channel(PUCCH), or wherein a HARQ time sequence K1 value of the set of HARQtime sequence K1 values is a time relationship between a time unit of aPDSCH and a time unit of a physical uplink shared channel (PUSCH); andreceiving HARQ feedback information, wherein a quantity of HARQ feedbackinformation bits is associated with the set of HARQ time sequence K1values and the time unit format information, wherein the quantity ofHARQ feedback information bits corresponds to a first time unit set, andthe first time unit set excludes a time unit for uplink transmission. 2.The method according to claim 1, wherein the time unit formatinformation comprises one or more of: a quantity of time unitsconfigured for bearing uplink transmission in one configuration periodor a quantity of time units configured for bearing downlink transmissionin one configuration period.
 3. The method according to claim 2, whereinthe quantity of HARQ feedback information bits is associated with a sizeof the set of HARQ time sequence K1 values and the quantity of timeunits configured for bearing uplink transmission in a time window. 4.The method according to claim 1, wherein the first time unit set isobtained by excluding the time unit for uplink transmission from a timewindow according to the time unit format information, and the timewindow is determined based on the set of the HARQ time sequence K1values.
 5. An apparatus, comprising: at least one processor, wherein theat least one processor executing programming instructions instructs theapparatus to perform operations comprising: sending a set of hybridautomatic repeat request (HARQ) time sequence K1 values and time unitformat information, wherein a HARQ time sequence K1 value of the set ofHARQ time sequence K1 values is a time relationship between a time unitof a physical downlink shared channel (PDSCH) and a time unit of aphysical uplink control channel (PUCCH), or wherein a HARQ time sequenceK1 value of the set of HARQ time sequence K1 values is a timerelationship between a time unit of a PDSCH and a time unit of aphysical uplink shared channel (PUSCH); and receiving HARQ feedbackinformation, wherein a quantity of HARQ feedback information bits isassociated with the set of HARQ time sequence K1 values and the timeunit format information, wherein the quantity of HARQ feedbackinformation bits corresponds to a first time unit set, and the firsttime unit set excludes a time unit for uplink transmission.
 6. Theapparatus according to claim 5, wherein the time unit format informationcomprises one or more of: a quantity of time units configured forbearing uplink transmission in one configuration period or a quantity oftime units configured for bearing downlink transmission in oneconfiguration period.
 7. The apparatus according to claim 6, wherein thequantity of HARQ feedback information bits is associated with a size ofthe set of HARQ time sequence K1 values and the quantity of time unitsconfigured for bearing uplink transmission in a time window.
 8. Theapparatus according to claim 5, wherein the first time unit set isobtained by excluding the time unit for uplink transmission from a timewindow according to the time unit format information, and the timewindow is determined based on the set of the HARQ time sequence K1values.
 9. A method for processing feedback information, the methodcomprising: receiving time unit format information and a set of hybridautomatic repeat request (HARQ) timing K1 values via radio resourcecontrol (RRC) signalings, wherein each HARQ timing K1 value of the setof HARQ timing K1 values represents a time difference between a timeunit for transmitting and bearing a physical downlink shared channel(PDSCH) and a time unit for transmitting a physical uplink controlchannel (PUCCH), or wherein each HARQ timing K1 value of the set of HARQtiming K1 values represents a time difference between a time unit of aPDSCH and a time unit of a physical uplink shared channel (PUSCH),wherein the PUCCH or the PUSCH is for transmitting HARQ feedbackinformation corresponding to the PDSCH; determining HARQ feedbackinformation, wherein a quantity of HARQ feedback information bits isassociated with the set of HARQ timing K1 values and the time unitformat information, wherein the quantity of HARQ feedback informationbits corresponds to a first time unit set, and the first time unit setexcludes a time unit for uplink transmission; and sending the HARQfeedback information.
 10. The method according to claim 9, wherein thetime unit format information comprises one or more of: a quantity oftime units configured for bearing uplink transmission in oneconfiguration period or a quantity of time units configured for bearingdownlink transmission in one configuration period.
 11. The methodaccording to claim 9, wherein the quantity of the HARQ feedbackinformation bits is determined by: determining a time window based on asize of the set of HARQ timing K1 values, wherein the time windowincludes one or more time units; based on the time window comprising thetime unit for uplink transmission according to the time unit formatinformation, removing the time unit for uplink transmission from thetime window; and determining the quantity of the HARQ feedbackinformation bits based on the first time unit set obtained afterremoving the time unit for uplink transmission.
 12. The method accordingto claim 9, further comprising: obtaining a first uplink time unit forthe HARQ feedback information; obtaining a second uplink time unitindicated by a K1 in a downlink control information (DCI) correspondingto a PDSCH in a time window corresponding to the first uplink time unit;and based on the first uplink time unit not being the second uplink timeunit, setting a corresponding bit in the HARQ feedback information inthe first uplink time unit to NACK.
 13. An apparatus, comprising: atleast one processor, wherein the at least one processor executingprogramming instructions instructs the apparatus to perform operationscomprising: receiving time unit format information and a set of hybridautomatic repeat request, HARQ, timing K1 values via radio resourcecontrol (RRC) signalings, wherein each HARQ timing K1 value of the setof HARQ timing K1 values represents a time difference between a timeunit for transmitting and bearing a physical downlink shared channel(PDSCH) and a time unit for transmitting a physical uplink controlchannel (PUCCH), or wherein each HARQ timing K1 value of the set of HARQtiming K1 values represents a time difference between a time unit of aPDSCH and a time unit of a physical uplink shared channel (PUSCH),wherein the PUCCH or the PUSCH is for transmitting HARQ feedbackinformation corresponding to the PDSCH; determining HARQ feedbackinformation, wherein a quantity of HARQ feedback information bits isassociated with the set of HARQ timing K1 values and the time unitformat information, wherein the quantity of HARQ feedback informationbits corresponds to a first time unit set, and the first time unit setexcludes a time unit for uplink transmission; and sending the HARQfeedback information.
 14. The apparatus according to claim 13, whereinthe time unit format information comprises one or more of: a quantity oftime units configured for bearing uplink transmission in oneconfiguration period or a quantity of time units configured for bearingdownlink transmission in one configuration period.
 15. The apparatusaccording to claim 13, wherein the quantity of the HARQ feedbackinformation bits is determined by: determining a time window based on asize of the set of HARQ timing K1 values, wherein the time windowincludes one or more time units; based on the time window comprising thetime unit for uplink transmission according to the time unit formatinformation, removing the time unit for uplink transmission from thetime window; and determining the quantity of the HARQ feedbackinformation bits based on the first time unit set obtained afterremoving the time unit for uplink transmission.
 16. The apparatusaccording to claim 14, wherein the operations further comprise:obtaining a first uplink time unit for the HARQ feedback information;obtaining a second uplink time unit indicated by a K1 in a downlinkcontrol information (DCI) corresponding to a PDSCH in a time windowcorresponding to the first uplink time unit; and based on the firstuplink time unit not being the second uplink time unit, setting acorresponding bit in the HARQ feedback information in the first uplinktime unit to NACK.
 17. A non-transitory computer-readable storagemedium, wherein the computer-readable storage medium comprisescomputer-readable instructions, wherein the computer-readableinstructions, when executed by one or more processors, cause a deviceperform operations comprising: receiving time unit format informationand a set of hybrid automatic repeat request (HARQ) timing K1 values viaradio resource control (RRC) signalings, wherein each HARQ timing K1value of the set of HARQ timing K1 values represents a time differencebetween a time unit for transmitting and bearing a physical downlinkshared channel (PDSCH) and a time unit for transmitting a physicaluplink control channel (PUCCH), or wherein each HARQ timing K1 value ofthe set of HARQ timing K1 values represents a time difference between atime unit of a PDSCH and a time unit of a physical uplink shared channel(PUSCH), wherein the PUCCH or the PUSCH is for transmitting HARQfeedback information corresponding to the PDSCH; determining HARQfeedback information, wherein a quantity of HARQ feedback informationbits is associated with the set of HARQ timing K1 values and the timeunit format information, wherein the quantity of HARQ feedbackinformation bits corresponds to a first time unit set, and the firsttime unit set excludes a time unit for uplink transmission; and sendingthe HARQ feedback information.
 18. The non-transitory computer readablestorage medium according to claim 17, wherein the time unit formatinformation comprises one or more of: a quantity of time unitsconfigured for bearing uplink transmission in one configuration periodor a quantity of time units configured for bearing downlink transmissionin one configuration period.
 19. The non-transitory computer readablestorage medium according to claim 17, wherein the quantity of the HARQfeedback information bits is determined by: determining a time windowbased ona size of the set of HARQ timing K1 values, wherein the timewindow includes one or more time units; based on the time windowcomprising the time unit for uplink transmission according to the timeunit format information, removing the time unit for uplink transmissionfrom the time window; and determining the quantity of the HARQ feedbackinformation bits based on the first time unit set obtained afterremoving the time unit for uplink transmission.
 20. The non-transitorycomputer readable storage medium according to claim 17, the operationsfurther comprising: obtaining a first uplink time unit for the HARQfeedback information; obtaining a second uplink time unit indicated by aK1 in a downlink control information (DCI) corresponding to a PDSCH in atime window corresponding to the first uplink time unit; and based onthe first uplink time unit not being the second uplink time unit,setting a corresponding bit in the HARQ feedback information in thefirst uplink time unit to NACK.